IME tubeless rims and tubeless tyres are likely to be more difficult to fit, more difficult to inflate, more difficult to remove, and are more likely not to fit well enough to be used at all.
Then I'd suggest your experience of tubeless (as opposed to your opinions about and prejudice against them 
) is limited. First time inflation can be a pain on 28's (25's have always been fine for me), but CO2 solves that. Like ZigZag I've never had to use levers to install a tubeless tyre, tho I do use two to remove them - much like tubed tyres I've used unless they've been very supple and fragile racing tyres. And if you use Marathons for touring, you'll have to make more effort that that! And ultimately of course tubeless can be tubed in extremis. And carrying a spare tyre (assuming it's folding) isn't really much effort, not that I ever did or needed to. Just lucky I guess.
Where I agree it can be a bit of a pain is in initial sealing to the rim, but not always.
I've not tried every combination on the market (any more than I have with tubed tyres....
), but I've seen enough to draw the conclusion I mentioned above. Any previously unknown combination of tyre and rim is a bit of a lottery, but with tubeless tyres/rims it is a bit more of a lottery than most, with all tyres tending to be on the tight side with tubeless rims, but not necessarily secure despite this.
Not all tubeless rims are created equal by any means and some (esp those without hook beads)
may not allow you the (useful when touring) fallback of safely running some tubed tyres on them without risk of them blowing off the rim. One would expect to be able to run a good quality tubed tyre from a leading manufacturer on a similarly specified "tubeless ready" rim but sadly this doesn't always work.
Note that hook beads are
not a reliable method of retaining tyres with no tubes, since whether the tyre is usefully pushed into the hook or not depends on exactly where the seal is made. Accordingly tubeless tyres are made with thicker beads (that are less stretchy) and/or are made a much tighter fit on the rim. Of necessity they won't come on and off the rim so easily. Between the extra rubber in the side wall required to make them remotely airtight and the extra weight of the stiffer bead, there may be at least half an inner tube's worth of extra weight there, and once the tyre has some sealant in it is liable to roll more slowly than the tubed equivalent.
The way tubeless tyres fit is also different in another way; the rim well is always shallow and the rim lips are nearly always less tall (typically by 1-2mm) than for a tubed rim. This looks great on the drawing board but it doesn't always stack up in practice; to make this work (with any tyre) requires greater precision regarding dimensions of both tyres and rims. IME no manufacturer (especially not many of those pushing tubeless tyres) has in the past shown themselves capable of making consistently sized tyres, anywhere near good enough to fit consistently (and safely) on such rims.
In a curious parallel forty-odd years ago a leading tyre manufacturer (Michelin) launched a new car tyre/rim design (TRX) with smaller rim lips, a shallower rim well, a bigger lip in the rim well (which ought to retain a deflated tyre better) and a tighter tolerance on all the dimensions. Of course it was never going to be compatible with standard tyres (they might have just blown off the rim, and certainly wouldn't have been secure in the event of deflation) so, (perhaps to their credit), they made the rim dimensions entirely incompatible with standard rims. The result was that the TRX tyre was never popular with consumers (tyres were expensive and there was very limited choice), the 'benefits' could anyway be obtained by simply making extant tyres slightly better, tyre fitters hated them (because they were usually a PITA to fit) and the available tyres were not that good. Michelin quietly dropped the idea after about ten years, and whilst you can still buy TRX tyres for some cars, they are prohibitively expensive; between double and about eight times more than conventional tyres. Most folk have had to buy new wheels for their cars.
Michelin have been notable because they (and one or two other manufacturers) have not embraced tubeless bicycle tyres. Maybe it is once bitten twice shy, maybe it is because they know that what we are being sold is a pup; the idea that 'there is no harm in having tubeless compatible rims' is just wrong, and that it cannot be expected to work like that.
cheers
