It's not as bad as it seems. Your rims still need tape if you're running tubes, so that's already taken care of. Going from bare rim to ready to rock is as easy as tape, install valve, mount tire, add sealant, inflate.

If a tubeless tire gets a flat in the field that can't be plugged by sealant or a tire plug (95% of flats are covered by those two), all that needs to happen is to dismount one side of the tire (just like with a tube), unscrew/remove the tubeless valve, dump the sealant, boot the hole, and install a tube just the same as a non-tubeless setup. If a hole is big enough that a tire plug can't solve the issue, the tire goes in the garbage as soon as I limp home. I wouldn't run a tubed tire with a hole that big either, but I might be picker than most when it comes to acceptable tire damage.