Out of combat, wizards are comparable to martial characters (except rogues) in terms of non-magical, skill-based capabilities, but they also have access to spells that can completely transform the state of an adventure (teleportation, scrying etc.).
Yeah exactly.
If it comes down to point, this is it. Wizards get to be about as good, sometimes better, than Martials in combat (very rarely worse). That's actually kind of fine.
But then they get:
100% of the power of Martial character out of combat (arguably more because so many skills come off INT and only one comes off STR). Rogues can get a bit ahead, but nowhere near enough to be as important as the spells a Wizard can cast.
AND
Spells that means they can do countless things better than any Martial character out of combat. Some of them are Rituals and don't even use a slot (not many, I admit). But you have slots to spare anyway, so you can completely work around entire skill-based challenges, come up with all sorts of creative solutions only magic can allow. That's kind of cool, for sure, but it's a huge design issue.
This is a totally unnecessary disparity that is
100% pure sacred beef USDA and WotC-approved. Just totally unnecessary. 4E even had the same ridiculous problem! Why doesn't a Fighter have any real, serious non-combat punch? There's no reason they couldn't have, say, eight skills, or Expertise in a couple of things (why does a Rogue or Bard get Expertise in Athletic but not bloody He-Man? Madness). No reason they couldn't have special abilities. No reason Battlemasters shouldn't get their non-combat manuevers from a separate pool to their combat ones. No reason more characters can't have Reliable Talent-type stuff - again, a bloody caster gets it (Eloquence Bard - and I admit Bards SHOULD have Reliable Talent with Persuasion), but not a Fighter, not a Barbarian, not a Ranger? A Ranger doesn't get Expertise or Reliable Talent with bloody NATURE?!?! WHY NOT!!!
I could go on. Beyond the skill system they should have neat, appropriate abilities for out of combat that spells don't just go "Pffffft" to .