Really that's the problem. Wizards have too much access to spells. They needed to be more limited, like old school specialization, which locked off two schools of magic. All magic all the time, with no particular need to worry about, say, having spells laying around to heal party members or remove afflictions like the Cleric, on top of their ability to have a bunch of spells prepared at once and being able to choose which one of them they need when they go to use a spell slot (stealing a chunk of the Sorcerer's thunder), has just made them too versatile. Add Ritual magic to the mix, and you almost can be Schrodinger's Wizard, able to blast, buff, debuff, dominate in exploration, set up indestructible bunkers to sleep in, and anything else you might care to do.
And concentration isn't the limit it's intended to be, since now, instead of knowing I can expect some buff spells to be cast on the martials, the Wizard is like "well I could Haste you, but then I can't cast (defensive or crowd control spell of choice). Sorry man, no can do."
Heck you can't even cast Fly on more than one guy to help your party get past obstacles! But hey, everything is fine guys...