It’s possible that some day in the future bitcoin may he converted to proof of stake also.
That's not going to happen. The core reason Bitcoin is the hardest money that's ever existed is because of proof of work. Part of why Bitcoin has monetary value is due to the energy used to produce Bitcoin and to secure the blockchain.
Eth 2.0 is unproven so far; it certainly wouldn't be trusted as a global reserve asset in its current form.