It's not much effort. You basically write an image to an SD card, put it into a pi and you're up and running. Although it doesn't block everything that ubo does, it does a darn good job and it's also effective for devices where ubo isn't an option. It updates the list on its own. I occasionally update it when I happen to log in to check something and I notice the software is out of date.

I don't think it's a situation where you can ditch your ad blocker if you are dead set on never seeing an ad. It may be good enough for most people though. Personally, I still run ad blockers on my devices. Other people in the household do not.

I seldom have to whitelist anything. I may not have whitelisted anything at all. I have blacklisted a few extra domains - things like analytics requests for IoT devices. I don't recall a time that something didn't work and I had to fiddle with the pi-hole to fix it. It's been very low maintenance and very effective in my experience.