ARURF hasn't been fun in years
Simply put ARURF just isn't fun, a sentiment shared by quite literally every other person I have met who plays this game. The fact of the matter is that URF is impossible to balance, and making the game All Random doesn't add anything interesting to URF, all it does is take away choice from the player. Every single game is almost guaranteed to have one of the many broken champions, and ARURF legitimately makes winning/losing completely irrelevant and entirely unsatisfying. URF should be in the draft format, and I'm generally curious if anyone could give a satisfactory reason as to why it isn't. Making a game mode where the champion you play (and therefore whether you win or lose) is based entirely on RNG isn't fun, it's just sloppy and lazy from developers who clearly don't care at all. While yes, some champions would be picked a lot more than others, but that's why the ban system in draft is there anyway.
TL;DR - ARURF is an already poorly designed game mode that is made genuinely unfun by the fact that it's random.