As I told you months ago, sleazy dirtbaggery and active promotion of ignorance is the norm in this industry. You have people unqualified to write a single blasted line of HTML or CSS making these derpy frameworks, and then people even LESS qualified using them, or in positions of power to dictate that you must use them.
NOBODY in the entire process seems to have learned enough of the underlying languages to flap their yap on the damned topic, but thanks to propaganda techniques like card stacking, bandwagon, and glittering generalities the masses yum up the bald faced lies as if it were the gospel.
See the "well you're just a beginner" attitude, where that's JUST another of the many lame excuses used to cover up
THEIR OWN IGNORANCE! It's little more than survivorship bias -- and a dose of confirmation bias -- in action. They've done it just long enough to have confidence, but not long enough to realize they basically know nothing... but because they can get
A result -- ANY result no matter what utter shite it is -- they are convinced they're doing it right... because it's what all the other lemmings are doing, because it "works for them", because it seemed "easy" and "made sense"
When in their ignorance they don't know that the majority of people can in fact be wrong, or that what they're doing is even harder than need be, and may not in fact make a lick of sense.
They believe the lie because they WANT it to be true, and then like cultists use echo-chambers, threats, and abuse of power to maintain that lie. Hitherto the creation of all these dens of suck-ups and sycophants who will let such underhanded, two-faced, duplicitous lies continue to be peddled and promoted as the greatest thing ever, so long as nobody uses any naughty words or says anything negative. Hence why MOST web development forums have a nasty problem with toxic positivity.
You said it yourself over on DP a while ago. These people are FRAUDS. Nothing more, nothing less. That they are successful is no more a testament to their being right than the nutters who run Whole Foods, Amway, rant and rave about the evils of vaccines, peddle "superfood" idiocy, or talentless whackjob actresses who tell people to shove jade eggs up the holiest of holies.
I don't find it depressing; it's infuriating the LIES these people believe as if it were the gospels, the delusional excuses they make, and the utter and complete nonsensical gibberish they spout about all of this chazerei.
In a way though I've been lucky on dealing with this the past 8 to ten years, as I've been the one coming in with the authority to tell these snake oil peddlers to stick it. Hence often those running companies like the one you appear to work for or in-house developers who promote the same practices are "the enemy" who find themselves either fired or in court for their ignorance...
... because you use ANY of this crap and follow any of the practices they promote --
jQuery, Vue, React, Bootcrap, turdpress -- in certain industries --
Medical, banking, public utilities, government -- it is only a matter of time in most nations before you run afoul of laws like the US ADA or UK EQA/DDA either through civil or criminal litigation.
Which of course these know-nothing derps then run their mouths about "not being a thing' and "no website would ever get sued for accessibility" -- PROOF they're talking out their arses!
You'd think the Domino's lawsuit would be a wake-up call, but instead they attack the guy suing instead of the dipshits who couldn't program a website properly... no that might endanger those people's future.
You'd almost think it was a rape case; attacking the victims being the societal norm. Oh no he's a college athlete with a bright career ahead, we can't ruin his life over 5 minutes of action.It's actually the same mentality, a way to let the rank and file sleazy predators continue to prey upon those who just don't know any better; and to attempt to silence anyone who DARES to speak out against these wolves in sheep's clothing.
Wherefore your being told "You're still just a beginner" is nothing more than an ad-hominem attack to undercut your credibility without presenting any counterpoint. They might as well have told you to sierra tango foxtrot uniform. No different than other passive-aggressive BS like "I'll pray for you" or "we'll have to agree to disagree". Lame limp excuses for the simple fact they have no defense and would lose any proper debate, but want to strut around with a fake moral superiority as if they won.
But again, people would rather accept a comfortable lie than an uncomfortable truth. That's why people trying to spread truth are most always pariahs, whilst those lying through their teeth are held up as paragons... regardless of if we're talking industry, business, religion, or politics. The biggest bullshitters always rise to the top like dross in a forge.
... and that's the biggest problem with these "frameworks". They say what people WANT to hear, not what they need to hear. Hence why so many are easily duped into believing utter and complete unfounded nonsense.
Also why when trying to defend frameworks, 99% of the replies fall into the bottom half of this chart:

Because they cannot actually defend their viewpoint with facts. So they attack the messenger, complain about how things are said, or start using insults without saying WHY. Every response being utterly devoid of facts or even a rational counterpoint. They use any and every lame excuse to dismiss dissenters without once using a valid counterpoint, because it's just "how they feel" about it.
Personally, I feel that letting such "feeling" override fact is one of the most dumbass things a person can do. I could go into even more detail, but then I'd have to move my own post to "the zoo".
As it is, I've probably danced well over that line.But then those of use who see the truth are the ones who are the problem. Of course we are.
Seriously, your boss sounds EXACTLY like the type of person I've either gotten fired or testified against in court... or just plain walked out on and watched crash-and-burn within months or even just weeks. I'd love to go ten verbal rounds with the know-nothing; "Send him unto me, I would have words with him."
Evil is evil -- lesser, greater, middling -- makes no difference. The degree is arbitrary, the definitions blurred. If I'm to choose between one evil and another, I’d rather not choose at all. -- Andrzej Sapkowski, The Last Wish