A complex subject for sure! Especially since bitcoin is - like Nostr - cross platform. You might be “spending bitcoin” that you bought on Strike for $65k (capital loss) or you might be spending bitcoin on Strike that you acquired off Strike for cheaper years ago (capital gain).
There are incentives for the wallet apps to try to build tax optimized optimization software for their internal transactions, but there are also reasons why the wallets should let more optimized software empower the user to select the bitcoin that is being spent based on other economic activity (potential intrinsic desire to offset capital gains or losses from other asset classes with the same year.)
Most importantly, since it’s a clusterfuck currently we should be petitioning our governments to have no tax benefits/penalties on commodity losses/gains (especially on transactional level payments up to x amount equivalent in fiat) to attract money to your nation and become more prosperous going forward.