Such problems are few and far between, though, and it wasn't that hard to figure out what to whitelist (granted I'm a computer nerd, not everyone is).
Now every time, I have an issue with any website, my first instinct is to turn off pi-hole. Most of the time, pi-hole is not the even the issue, but sometimes it is. It's annoying to browse the internet while constantly thinking "Maybe there is an issue on my side".
It is very rare that I find something stalker-blocking (pihole on my local network & VPN) causes to break that I care enough to turn blocking off for. It might have happened as little as twice, one of those occurrences predating PiHole. Information is usually in many other places or I really don't care that much, and shopping sites that break are waving a red flag by being broken so I'll go look elsewhere.
I do have a bookmarklet on my devices to turn it off for a few minutes, but that was used more when testing it then it has been since.
I mostly live alone so don't have the problem of other users, such as a spouse or kids, having trouble. Guests always have the option of using their normal mobile access instead of the local wireless if they experience insurmountable problems.