One, sometimes I want to browse/buy things via Google Shopping (or some other shopping interface) but the Pi-Hole blocks it.
Two, sometimes for work I will run a docker-compose script that say, downloads a copy of Puppeteer. For whatever reason the domain seems to be on Pi-Hole's blacklist.
Granted I could probably whitelist the domains but that seems like a hassle. It has the ability to disable blocking for periods (like 5 minutes or an hour) but that doesn't seem to solve the above problems.
Other than that, it works great. It probably won't affect a regular internet user. But occasionally you can run into problems.