Bitcoin is not gambling and gambling is centralized, which makes it easy for some countries that banned it to reconsider lifting up the ban from gambling. They have cone to realize that it can be a source of revenue to the government.
As decentralized as Bitcoin, most people choose to use Bitcoin in centralized way, making it easier for government to take action.
The government can create their own exchange and force people to use their exchange, if they use foreign exchanges, the banks will freeze the money.
This also applies to gambling, Thailand do legalize gambling, but not all people are gamble in their casinos, some of them might gamble on unauthorized online casinos.
It's easy to bypass the centralization. Trade Bitcoin using DEX, hold in non custodial wallet.
The government have no way to eliminate Bitcoin decentralization, it was never under their control, Bitcoiners always have a remedy of controlling their assets.
Governments can be picky, they can keep Bitcoin as a reserve but may not be fully bound to the system, this reason i am afraid for what the government can do if they keep the pace of legalizing and accumulating large portions of Bitcoin as reserves, not just one government becoming whale but sine it has become a new order for countries to adapt.