Hiya!
Titles says it all, almost...
Am I the only one?
Brave question to ask! (here's an xp fro having some moxie). Many 5e folks...me included...are quite happy with the Concentration rules.
That said, I can see your point, and for a select few spells I agree that Concentration should be removed...with a caveate.

I think a few spells should be able to be "ritualized", and if so done, become non-Concentration; just a flat duration. I like the idea of Ritual Casting, but they didn't go far enough with it, IMHO. They basically just boiled it down to a simple "Oh, you take more time to cast it". B-o-r-i-n-g! But that's another post all together.
I would suggest trying a house-rule of "2 Concentration spells allowed at a time" and see how that affects your game. If things start to get too..."wonkey"...then there's your answer; keep Concentration as is. If it makes your game better, great! Keep going with that!
As I said, for me, SOME spells I think could loose the Concentration aspect, but I'm happy with the way they are right now none the less. We play with them RAW, basically. Maybe if/when the PC's hit a level higher than 7th (nobody in my campaign has ever cracked that level), I'll revisit the Concentration rules. Maybe.
^_^
Paul L. Ming