I installed tubeless 32mm GP5000's over the summer, just to try it out.
The initial install and setup was a pain. The tires were super hard to mount on my rims. They inflated easy enough with a floor pump and one of those dump tank/air shot things, but I couldn't get one of them to seal up, and it kept going flat after a few hours. I eventually took it to my LBS and paid them to do it. I think they re-taped the wheel (which had factory tubeless tape installed).

Since then, I've had zero issues. No flats all summer, the tires are super comfy and fast. I run them at around 65-70psi. I added more sealant a few weeks ago, because the internet told me I should. This is really straightforward and not messy at all... just let the air out, unscrew the valve core, add sealant with an injector thingy and pump the tire back up. Takes about 5 minutes.
Other than that, they've been maintenance free. I do worry about getting a roadside flat that I can't fix with a plug, even though I carry a spare tube it would be a huge pain to get the tire off and back on the rim.

The only reason I'd go back to tubes is that I'm concerned about swapping tires and going through that initial setup pain again. A second set of wheels (one for road, another for gravel) will solve that problem.