A will disagree. I've been using tire liners for almost 15 years. They allow me to enjoy less-expensive, lighter tires with soft, supple sidewalls, while preventing the goat-head thorn punctures I used to get.

I tried stiffer, heavier puncture resistant tires that cost more, and while they prevented goat-head punctures, there were un-fun drudgery to ride.

I can't speak about sealant...I've never used it. But sealant seems like a better choice than heavier, stiffer tires.

I've also never run tubeless, so I can't comment on that.

But I've been very happy with my Mr. Tuffy's.