To be fair, both disc brakes and tubeless tyres are a significant improvement ...on a mountain bike.
Personally, I find disc brakes easier to set up than rim brakes, because with a decent one you've only got to jibble one parameter at a time. This seems to be a minority opinion, which I suspect comes from most people here having a lot more rim brake fettling experience than I do. But even if they are more faff, they're worth it as soon as you care about consistent performance in the wet, or rim wear. It's a reasonable trade-off, at least some of the time.
Similarly, I don't think anyone sold tubeless tyres as less hassle. It's a way to avoid snakebites and reduce rolling resistance. I suppose it saves all the hassle of smaller punctures up for when you eventually get a big one.