I'm not sure that I've seen any tube type only tires in a long time. At least not for a road bike.
A tubeless tire designation itself will not necessarily be less prone to coming off of a rim, the individual tire design has more to do with that. A rapid and complete air loss is going to be a problem for any tire. But in the most common situation with a nail or screw in your tire, a tubeless type will generally lose air more gradually, giving you fair warning. However a tube will deflate more quickly under every scenario.
I've done the Outex kit myself, and it takes time and patience.
However it takes far less time and patience, and is much safer than getting a flat with a tube tire out on the road in the middle of nowhere, in the dark, without cell service, tire lube, big ass irons, a pump, a few extra tubes as you pinch one or two, and a jack in your tool kit in case it's the front wheel.
Personally, the tube type wheels were the biggest impediment to actually deciding on getting the bike. I knew, before I even got it, that I'd be doing the tubeless conversion. I've had flats on the road over the years on various bike, and always had a plug kit for them. It's easy and safe to do, and generally won't ruin your day.
I was on a ride with a guy on him Moto Guzzi California a few years ago. We were miles from home and he got a flat. No center stand, no tools, no spare tube, nothing, nada, bupkis. His choice was either a $300.00 tow truck, or one of our riding buddies rode home, got his trailer and van, and drove back to pick him up.
That said, many people are fine with tubes.