Problems exist with both tube and tubeless systems. No prefect system really.

Tubeless negatives:
Cut tire (you'll need a tube to continue)
bust rim (no seal, tire won't inflate)
Cracked rim (can happen with some cast wheels)
Weight (tubeless spoked wheels can be heavy)
If bead ever does break (unlikely) .. can be a PITA to get it to inflate.

Tube negatives:
PITA removing wheel, breaking down tire/changing tube, remounting.
Packing spare tubes (but really required with BOTH systems)
Patch kit that actually works
Instant Air loss with big puncture (this can be dangerous)

Comment on SLIME or Ride-On or other products that go in your tube/tire before you get a flat:

It's true ... they don't always prevent a flat ... but often DO, especially if you run over a small staple, nail or cactus thorn. The sealer may not always 100% stop the leak ... but often can slow it down. This can allow you to ride ahead to a convenient place to do a repair.

But the MAJOR reason I run Slime (have done over 10 years) is to mitigate instant, catastrophic air loss. This is most worrisome on front tire when riding at speed on paved roads. Anyone ever had a flat when leaned way over in a corner at 70 mph with a tubed tire?

The rear can also "step out" if it goes instantly flat. All these things can kill you if you ride fast. A loaded bike is worse.

What SLIME, Ride-On or other products can help with ... is to at least slow down air loss ... giving the rider a warning and time to get safely off the road.

A few SLIME tips:
Some say it's messy. Did you know it's water soluble and rinses off clean in seconds?

Don't try to patch a tube with SLIME in it ... unless you have lots of time. Most times the SLIME will work the patch loose. It can be done ... but requires "technique".

Same goes with Tubeless tire plugs. If you have SLIME in your tire, the plug with slowly come out. It may hold for a while but may leak air or slowly work its way out. Happened to me on my 1050 Tiger. I got home riding
300 miles (airing up every 2 hours), then removed tire, washed out SLIME, remounted ... all good with new Plug installed.

Breaking down tires is an Art. Good tools and technique a must, along with good strength. Some tires are tougher than others to break the bead on.
Bring tools! When you think you're good at breaking a bead and changing a tube ... remember that ISDE guys can do it ALL in One Minute 30 seconds. (on average). Includes removing wheel, and reinstalling it.