The Difference with Team Builder
I am not a PVPer. I never have been. I enjoy LoL for the PVE elements and the champions themselves. I usually stick /universally/ to BOTS games. That's where I have fun, that's where I can relax.
Obviously, LoL is a PVP-focused game/industry unto itself. So I felt a certain nudge to /at least try/ PVP. It's not really ever a good experience for me, but it keeps building up periodically and I retry anyway.
Team Builder itself, the fact that it allowed ME to pick what champion and what role I was going to play, was a HUGE relief. 75% of my anxiety and stress about PVPing evaporated instantly, and as a result, I actually played PVP several times. Because I got to play who I wanted and /how/ I wanted, even the losses were at least enjoyable games.
The NEW pick system, especially with Team Builder /removed/, SPECIFICALLY re-creates the stressors. I get it, I know what the devs were going for, but I wanted to offer feedback from one small chunk of the population that kinda /needed/ team builder's specific setup to actually TRY PVP.
Now that Team Builder is gone, I have even LESS desire to PVP than I did /before/ Team Builder. I honestly haven't PVP'd since Team Builder was removed. It's just not worth it to me.
TL/DR: Team Builder encouraged a chunk of the LoL community to play that normally wouldn't leave bots. The new system doesn't.