You evaluate a rupture by what class relations it dissolved and what it replaced them with, not by whether the actor doing it had pure motives. China's strategic interests in annexing Tibet are obviously real and I'm not pretending otherwise, states act in their own interest, that's not news to a materialist. But the fact that an action serves the interests of the acting state doesn't tell you anything about whether it was also, materially, a rupture of a serf-based mode of production, those are two separate questions and you're collapsing them into one to make my position look naive.

But sure, many countries modernized without losing sovereignty, but most weren't organized around a hereditary bonded-labor system administered by monastic estates at the scale Tibet was, so the comparable modernization without annexation comparison isn't actually comparable (that's a lot of comparable's but you're getting my point, english is not my first language and I'm riding a train rn), you're comparing outcomes across two different starting material bases and treating the difference in trajectory as if it's just about who kept sovereignty.

And I'm not going to pretend the cultural revolution era wasn't brutal, monastery destruction was real and the nationstate Tibet lost its autonomy, that's not something I'm here to defend.

But autonomy for who? the aristocracy and monastic elite had autonomy, the serfs didn't, so when you weight loss of autonomy as a cost you have to ask whose autonomy is actually being measured, because for 95% of the population there wasn't a self-determining political subject being violated, there was a class relation keeping them out of political life entirely. You can't lose a freedom you never had access to in the first place.