I tried out PUBG a few years ago back when it was just the 'Battlegrounds' mod for ArmA III. It is quite fun, to be fair - It evokes a lot of 'Hunger Games' vibes in the way you need to find a weapon, stay alive and ahead of the shrinking world and ultimately find and kill your opponents to come out on top.
I don't really understand what's made BR popular right now - maybe just a perfect storm of circumstances - but I can somewhat appreciate their appeal and the surprisingly high level of tactical depth that can go into these games.
But you're right the UI and controls makes these games an entirely different beast on mobile. Whether they have any staying power remains to be seen, but you can't fault them on their business model at least - it's purely cosmetic driven.
"Determining the appropriate level of influence in somebody else's war is never a simple matter."
- Special Circumstances