Reasons for XMR to potentially to overtake BTC. I'm not predicting this just throwing out reasons why it could happen.

1. Pure stupidity of crypto markets i.e. anything is possible. e.g. Verge could overtake BTC.
2. Tail reward comes to forefront as a confidence crisis over stability
3. On-chain fungibility advantage recognized as crucial
4. RandomX is a huge success (large and widely-distributed mining network becomes a clear advantage, contributing to a confidence flip)
5. Flexible blocksize results in significantly better on-chain scalability without a bloat explosion that destroys decentralization.