Wizards are more than fine in 5e, it's the Bg3 adaption of the ruleset is questionable. Concentration has already been mentioned and the controll spells being nerfed. Additionally BG3 is littered with OP melee weapons and gear which drastically changes the power balance between the classes. Add in no attunement and melee makes casters look like trash.
That being said, casters still add some tactical tools which can massively impact the battle. We are missing a critical gear type for casters though: spell foci. An Arcane Grimoire +2 increasing spell DC would be comparable to a +2 greatsword. We have a lot of weapons and gear for melee, very little that helps spell DC's. Casters seems to have been mostly forgotten in itemization that's useful and not just weird gimmicks.
No that is not true. Wizards are trash in DnD 5e but in BG3 it got even worse. The amount of spellslots is ridiculous and this is because of DnD 5e. Casters are much more fun in PF where all casters have access to metamagic FEATS not only sorcerer. WotC simplified the rules for 5e because the people are braindead and too stupid to choose proper feats for their class so there are not many feats left. If they do not want to give wizards metamagic they should give them some other good stuff instead. More spell slots per day for example
