I ran Pihole for many years, but a few months ago moved my home to Adguard. Both as docker.
My main issue with Pihole was that the database get going readonly which prevented my from whitelisting domains. It got progressivly more irritating when a 10 second operation would take a quarter of an hour and this randomly happened over at least two of those years with seemingly increasing frequency. A secondary reason was curiosity - what does Adguard do differently?
Piece of cake to set Adguard up in docker - even though I have two servers running with primary/secondary failover. In terms of features, it “just works”. User experience is identical. The lists seem equally as effective. Adding a local dns entry was a little more complicated, but not difficult by any means.
Is pihole bad? No, it’s great. I don’t think many other people encounter my specific issues.
Is Adguard better? Not by any massive margin. Both do what they claim to do without fuss.
Is browsing the internet without either of them considerably more awful? Yes.