I play aram exclusively and I agree with you completely. I came to the boards looking for a post about how now way more games are one sided stomp-fests. This is the only post I can find. Im really surprised there arent more posts about it and that this post got such unfriendly responses. Just because you don't know why its like this doesnt mean you dont know its happening, or cant write a post about it.
I too dont know why its happening, just that it is. From what I know about the changes I would have guessed they would improve balance and fun. Being able to pick up the champ which was rr is a really nice change. Before you had to depend on the person asking if anyone wants their champ and then waiting for everyone to process that. Also now you can pick up the rr champ even if the person who originally had it doesnt own your champ. It just seems like a really good change. I am at a loss as to why now almost every game is decided in champ select. Maybe its the individual tweaks to the champs themselves. IDK. I can't even tell ahead of time which side has the advantage. Its like now it really comes down to individual champs, not comps. Tank comp can dominate with the right champs, or can be completely ineffective with the wrong ones.
I wonder if the group healing change is part of the problem. It devalues champs which do damage over time and increases value of high burst. If you dont get the kill right away they just heal up.
Bottom line is I really dont know what is causing the problem but I do know Im already losing interest in aram because most games are now totally one sided.