I think it's still possible to apply OTA updates but the process is not automatic. In my experience it doesn't successfully apply the update and unroot you, it just fails. This is a very unpopular thing to do, but I turned off OTA updates and I don't plan on upgrading form Android 11 anytime soon. Even security updates failed to apply automatically. Sometimes you have to reset the entire OS, including installed apps, in order to update. I think you need to reset during the rooting process as well, as oem and bootloader unlock forces a full data wipe. It makese sense from a security point of view, rooting shouldn't allow someone to gain access to information on an already encrypted device. I strongly dislike the way Android is becoming more locked down, I'd rather risk a wild security exploit compromising my device over not having root access to my own files. In my opinion, not having the ability to access your own files is the same as dealing with a virus. I wouldn't ever reccomend someone else do I am doing. But it's something to think about while considering rooting.

I use Viper4Android. I am thinking I might intentionally upgrade to an older flagship, when I do get a new phone, because there's no feature a new OS will get which will make me want to give up root and V4A.

AdAway is nice, since it is a set and forget app, I forgot I have it installed. Firefox+ublock, youtube vanced, and DNS or VPN level adblocking are usually good enough for me and don't require root.