Yes, there are experimental LineageOS 20 (Android 13) builds for the M8. Android 14 is unlikely due to ART (Android Runtime) requirements. However, A13 is significantly slower than A12. For the M8, for performance and modern apps.
Despite this, the custom ROM community (specifically on XDA Developers) has refused to let this phone die. htc one m8 android 12
The HTC One M8 remains one of the most iconic smartphones ever built. Released in 2014, its brushed aluminum chassis and front-facing BoomSound speakers set a design standard that many still miss today. While HTC officially stopped updating the device years ago, the developer community has refused to let this legend die. If you are looking to breathe new life into your classic handset, installing Android 12 is the ultimate way to do it. Yes, there are experimental LineageOS 20 (Android 13)