If a major government wanted to break crypto, it would simply credibly threaten to launch a 51% attack. This is within the budget of most developed economies, and much simpler than enforcing a ban. Nobody does it because it would be stupid. Crypto is part of the economy. Destroying it would be akin to bombing a domestic factory because one doesn’t like its products.
Anyone who makes this argument likely stopped staying in touch with blockchain tech after 2016.
It's like people stopped paying attention after the last crash and assume the crypto space has stood still since.
Do you know how hard it's now to buy/produce graphic cards and asic-s good for mining crypto? The demand is very big yet producers can't scale up. I don't see governments to have possibility obtaining so much hardware in a short/medium time horizon.
There is not enough of them to buy on the market to make 51% attack. Of course seizing is possible but hard because I imagine it would be quite hard to locate them, apart form large mining operations they are quite distributed.
In case of bitcoin network it would have to be a large multicountry operation. Because the miners are really distributed around the world.