My experience, ARURF included.
I have played league for 3-4 years roughly, i have played all the modes that have been active in my time here. At first i was active with summoners and dipped my toes into ranked (S2 if you can even call that ranked, ya i suck get over it, i did) as time went by if i wanted to play summoners i only stuck with ranked cause tbh people are much less toxic then in norms, where you want to try something new but everyone else is trying to show how awesome they are on their rank 7 (no i didn't try new things in ranked, i'm not that guy). I eventually got to the point where there were nights where i would play 4-6hrs and end up further behind then when i started and more frustrated and began to wonder why i should bother (once again i know i suck) I then moved on to ARAM, at first not my thing, but when they got rid of teambuilder, rip, i couldn't do norms cause of the above, my wife and i stuck with this for some time. In the end, in the back of my mind i was always holding out, waiting for the next URF to come along, or game mode that i enjoyed, with the periodical stint in ranked, till i got frustrated. Regular URF is great, don't get me wrong, but i will take AR at the drop of a hat if i can't have anything else, and at times i love it and others i hate that i can't pick who i want. Once again, i'm a fan of both. But this mode gives me a feeling that i haven't experienced in a long while... FUN IMO it should be something regular, i don't see how people can survive on one mode and not get sick of it (showing more these days with users) and the only other option being aram. This mode is FUN, it doesn't need bans, it doesn't need adjusting, it just needs to BE. I'm sure that some will say, oh but they said that long term players leave after! well ya, some ppl are burnt out on the game for a long time, and stick around anticipating the next round of it, heck i stayed for a good year just waiting with baited breathe for it to come out again, but once it's done.... i know it won't be back for a long long time, so my journey is over for some time. Some will move on and find other games, some will move back to old games that actually provide them with options of more then 1 or 2 things to do, and some will continue to wait again. TBH i probably won't be going anywhere, i will continue to play so long as URF, and possibly One For All comes out periodically. But there's nothing holding me here if something better comes along, and i won't put any money towards the company as i have in the past and like others, i will not hesitate to jump ship, alot of us are only here cause we haven't found something better yet.
TLDR: I suck at ranked, i play aram some, i enjoy (AR)URF and one for all, LCS still cool, but doesn't mean i care about being competetive bring back Team Builder! BONUS: Why did Hecarim lose his passive to ignore unit collision years ago but Kassadin keeps his? Bring back top lane Hecarim!!