My goodness. I have not heard that term "tubeless" in years. With the exception of a few suppliers of tires for antique car afficiandos no one sells tubed tires these days, unless you want to count those high-technology "run-flat" tires on a few high performance cars. Moreover, the terms tubeless and radial refer to two different aspects of tire design that have nothing to do with one another except that both the common introduction of radial tire designs happened to coincide with the introduction of tubeless designs.
Prior to the introduction of radial-ply tires, there were what were called bias-ply tires. The ply refers to the belts that support the outer tread on the tire. On bias-ply, these belts were affixed during construction of the tire at a 90 degree angle to the tread face, crossways if you will. It was later discovered that the tire could be made to provide better handling and longer service life if the ply, or belts were constructed criss-crossing one another at a more acute angle, usually 45 degrees, and this was referred to as a radial-ply design, which came to dominate the market almost entirely.
About the same time, manufacturers began to produce wheels that had no internal seams that would leak air--that is they were capable of being made air-tight. Accordingly, when the lip of the tire was properly seated on these wheels on both sides, and it was pumped up to make a seal around the edges, there was no longer a need to have an internal air bladder, or innertube as they called it, to contain the air inside the tire. This also had some advantages in terms of heat diffusion, as by eliminating the layer of innertube pressed against the inside of the tire wall it somewhat improved the tire's ability to dissipate heat away from the tread which is generated by the rolling friction of the tire on the road.
Accordingly, about the same time that radial tires came on the market, most of those tires were offered as tubeless tires as well. These days, with the exception of the antique restoration market, it is quite rare to find either a bias-ply tire or a tube-type tire on any modern vehicle.