Nowadays on Twitter we have individuals, and even companies like Blackrock, declaring that if BTC doesn't increase the supply cap (and thus become like Dogecoin [they don't say that but it's implied]) then it will eventually fall to 51% attacks.
These people don't understand about Bitcoin total supply, how it was capped by the Bitcoin founder, Satoshi Nakamoto, and how people dislike the idea of increasing the cap.
They don't understand that Bitcoin blockchain is Proof of Work, not Proof of Stake and if you hold more bitcoin, you don't have bigger power to attack the Bitcoin network.
How is the 21 Million Bitcoin Cap Defined and Enforced?How many Bitcoin confirmations is enough?Can Bitcoin's Hard Cap of 21 Million Be Changed?Can the limit be changed?
Technically yes, though this is really a question of governance and incentives. Anyone can change the limits enforced by their own node - the hard part is convincing everyone else to do the same with their nodes.