Does XMR solve the problems of Bitcoin?
No, because XMR does not scale. You need many thousands of tps and storage that only grows per-account not per-tx before you can even begin to call anything a scalable money that will continue to serve for decades. Prospective candidates also need lifetime cryptographic levels of privacy at least 128-bit equivalance of attack resistance regardless of whatever method they use to obtain their "privacy". They also need to be quantum resistant PQC, use TLS, work over darknets, interoperate with DEX protocols, not premine or monetize or govern or smart or defi, inflate below both gold and 0.25%, avoid issues with PoS, etcetera. Will any particular current or future coin become among this next-gen stripped-down L1 private cash for the world? Is it possible to do all this? Yes. But be careful in the analysis before shilling particular projects, essentially all of which are nowhere near having developed the tech, the roadmap, or even the philosophy needed to do it. Bring that day forth.