As someone who switched from PiHole to AdGuard Home a couple of years ago, my reason was because PiHole dropped support for adblock style lists that I was using, while AdGuard still supports them.

See here for more into

you can also go here: https://myactivity.google.com/product/youtube and set it to auto delete

I’ve found that if I remove things from my history, it stops suggesting related content, hopefully that helps.