Because that is their role.
Not if they’re being challenged.
Their job is to suck up attacks and get in the way of enemies fixing or holding them in place. Hit points are a limited use commodity. Ending the fight with the party losing the fewest resources is the goal.
Except the BS only tanks well if the DM is actively allowing it to do so, where nearly any other actual tank doesn’t need any help. A Fighter or Barbarian’s HP is much less limited, over the day, than anyone’s spells slots.
Maybe you play a game where shorts rests rarely happen? If so I find the comment below about RAW encounter building guidelines pretty humorous.
Sure everyone has weaknesses. I think a fighter in plate has bigger weaknesses though in terms of disadvantage on steath than anything you are going to point out on said warforged bladesinger.
Experience tells me to disagree. Maybe your DM is reluctant to deal big damage and sometimes knock out PCs, maybe it’s something else, but there is a reason that this thread is the only time I’ve ever seen anyone, anywhere, claim that BSs are good tanks.
Hell, just the opportunity cost of high Dex rather than max Int is being ignored here. You’re a Wizard. Your role is to cast spells. If you want to lock anyone down (a major tank goal) you’re gonna need that mod up. And concentration free for control and offensive usage.
The BS can, at level 6+, hit and cantrip, with flaming sphere, summon Fey/whatever else, spirit shroud, or use hideous laughter or hold person or faerie fire to have advantage and grant advantage to the whole team. Any of those are better for the team than the guy with 25 HP pretending to tank.
Well if we are bringing homebrew into it then we are not really playing the game RAW and the sky is the limit. RAW you should "exercise caution when using challange rating higher than the party's average level"
That is the game I am playing RAW.
Right. RAW is objectively incorrect, when it comes to CR. Even with right out of the PHB, so it isn’t a Bladesinger issue. In fact I find it easier to challenge a BS than to challenge an Evoker or Abjurer, but they’re all wizards. They all have low HP, garbage strength saves, mediocre Con saves, rarely train athletics, and have to spend a lot of their resources to do just about anything.
But we established earlier that you don’t see wizards spending spell slots out of combat, so, yeah, very different games.