I don't agree, concentration spell are very useful i have won several fights using hunger of Hadar as my only spell, cast your concentration spells and run or drink invisible potions, everything is viable with some creativity.
I also didn't have a hard time with keeping concentration because of dice rolls and found them pretty useful too for the most part. When my concentration broke it was complete user error lol. Or, me trying to cast something that took concentration without paying attention to that I had already cast something using concentration. WIth hunger of hadar it was fine, but in my game most of the time people would just jump/walk out of it TT TT Same with the fog one.
Most useful was the blade tornado lol
