The biggest win is getting a modern version of Android (like Android 12 or 13 via LineageOS) on hardware that Sony stopped supporting years ago. You get the latest security patches and access to newer app features that the stock firmware simply can't run.
If you tell me your main goal, I can help you pick the best custom ROM for your Xperia XA1 Share public link sony xperia xa1 custom rom better
Installing a custom ROM requires several critical steps that will and likely void your warranty. The biggest win is getting a modern version
