My take is that it's a bit varied. Tibetan Buddhism is basically the Catholicism of Buddhism - statecraft, absurd amounts of riches accumulated at the top, pretty brutal in terms of dealing with heretics and pagans, subsuming the local traditions and practices into their practices, preaching penitence and a life of austerity from atop gilded thrones and affording lavish lifestyles for the clergy, the institutionalised repression of nuns, taking a very simple and austere religion and turning it into lavish parades and ostentatious building and furnishings to wow people...

But then you also have some monks or lamas that are genuinely good people who do good work and aren't interested in personal gain or a life of luxury, just like what you can find in Catholicism.

You could make an argument that these people still support a fucked theocratic system and that they helped to maintain the good public image of the religious hierarchy and its excesses - I would find that argument compelling. You could also argue that these people were genuinely committed to doing their best by the people and I'd find that argument convincing too.

But yeah, there was tons of abuse and excesses generally amongst the Tibetan religious elite. Assassinations, coups, horse trading for political favours (reincarnations were pretty much exclusively recognised in wealthy and powerful families with the justification that lamas who had accumulated enough merit would be able to choose a "favourable" reincarnation; the contradiction implicit in such a justification being that a "low" birth means a life of immense suffering and deprivation but also it's a theological argument that people who were born as peasants deserved their station in life due to bad karma accrued in previous lifetimes [kinda sorta, but I'm not going to get right into the weeds on the Tibetan Buddhist theological position on how a human reincarnation was perceived because that's a long story]), conflict between schools of Buddhism as they vied for power...

[CW: CSA and SA discussion ahead]

...along with high ranking lamas sometimes taking "consorts", which was really just a religious justification for having a woman or a harem that were enlisted into sex servitude, and lamas taking peasant children (particularly boys) to be dancing boys - basically just a euphemism for child sex slavery.

There's a lot of dirt, both historically and in contemporary times, and that's just an overview of some of it - there's plenty more examples I can rattle off from the top of my head.

At one point I actually had a private audience with the most prominent Nyingma lama in the west at the time. The Nyingma school doesn't have a de jure head like the Gelug school has the Dalai Lama (again, kinda sorta but that's its own long and boring story) but this guy was definitely the figurehead of the Nyingma school in the west; maybe more like the star player of the team moreso than the captain. Anyway, of course all this shit kinda semi comes out about him being a sex pervert. And that's far from being the only case. Samye Ling monastery in Scotland, the first Tibetan Buddhist centre established in the west and known for being a place that attracts high flyer western celebs, is well known for being a hotbed of drug use and sexual abuses which goes right back to its co-founder Chogyam Trungpa.

Then there's all kinds of shit with the Dalai Lama - it used to be popular in airport bookstores and those shitty pop-up bookstores in B-tier malls to have all sorts of books written by the Dalai Lama when in reality he was just leasing his name and image to anyone who was willing to pay for it and he didn't have a hand in writing any of that shit. Or how he rode the wave of islamaphobia and sinophobia in the west amongst his followers while peddling the softer end of doomsday cult bullshit (not Alex Jones-style weapons grade doomsday cult but still). Or when a biographer interviewed him in India and noted that in his quarters there was a rifle - upon being quizzed about this and how it would be perceived by others, the Dalai Lama assured the biographer that it was just an air rifle that he used to scare away birds of prey (hawks? I forget...) while feeding pigeons. How you square the idea that an air rifle is going to shoot far enough to spook a hawk, how pigeons are just going to be hanging around feeding when there's a hawk lurking nearby, how an expert marksman like a Buddhist monk with coke-bottle glasses is going to spot a hawk before the birds do and how he would spot a hawk before it was within striking distance... that's all a matter of faith, I guess?
With "just a simple monk" like this, who needs politicians?

There's a big culture of pissing on people's boots and telling them it's raining in Tibetan Buddhism, or maybe more appropriately, pissing on people's heads and calling it a prayer wheel.

It's a rotten religious hierarchy, just like every other one to exist. There are some good people within it, there are plenty of awful people in it. If someone gets a lot from Tibetan Buddhism or they have a beneficial relationship to a lama then I'm glad for them but I have a pretty dim view of Tibetan Buddhism because of how it functions, especially historically, and what happens within the Sangha and how that gets excused and covered up.

I have zero patience for westerners who have this naive, idealised notion of Tibetan Buddhism being literally the ATLA Air Tribe because that's just a fairytale which sells books and speaking tours and shit like that.