Being a store of value and unit of international trade settlement are excellent use-cases for Bitcoin. Very soon users will be able to earn Bitcoin through DeFi, and I am optimistic about developments on Cardano to facilitate this. I understand some people wish for Bitcoin to be used for payments or micropayments, but I think being digital gold in a world of inflating fiat currencies is an important use-case.
Don't connect Bitcoin to DeFi that is bad in my opinion. Bitcoin is an unique cryptocurrency and also a best one so it's unnecessary to connect Bitcoin to low value, zero value altcoins and DeFi ecosystem.
Earning something from DeFi means that project and cryptocurrency in inflationary or very inflationary. In long term, this scheme of money supply only makes price plummet with time, and fortunately, you have Bitcoin that is not a project like this. Scammers will try to abuse Bitcoin name for their scam projects but if you are knowledgeable enough, you will not let it misleading you.
DeFi will increasingly play a role in the global monetary system, and Bitcoin will inevitably be used within it. One of the drawbacks for many holders of Bitcoin is the lack of a yield, as with many proof of stake coins through staking. I believe many Bitcoin users will gladly use a protocol that safely and securely offers them more Bitcoin. Numerous projects are working on this.