The main advantages these days are reducing reliance on Google [1], supporting open-source software, and extra security/privacy protections. Probably true that

The main advantages these days are reducing reliance on Google [1], supporting open-source software, and extra security/privacy protections. Probably true that the average poweruser perceives less value from them than before. Some of those advantages are more ideological and less concrete/measurable. Compared to the Pixel stock ROM, you aren't missing out on much, and you're gaining a few non-security bonus features, like unrestricted tethering, local/offline backups, call recording, and Network permission toggle [2]. [1] I don't really like the term "de-Googling" because it paints an all-or-nothing picture, despite alternative ROMs providing the option to use Google services in a safer and fairer way (fairer as in, non-Google apps are on a level playing field when it comes to OS integration). [2] This is most certainly intended as a security/privacy feature, but I find it useful as an adblocker as well :)