[Blewvane]

So was the stuka's original role an air superiority fighter? If so then yes it would have been at a disadvantage.

[Arkoquisa]

it was slow and maneuverability was limited and had fixed landing gear and had gone through a series of transformations through the 1930's before the war, head to head it was a sitting duck even with a rear gunner, but in its dives they reached over 500mph and were psychologically devastating with the siren (i read one account to where an entire village in russia departed after hearing one stuka siren and the one bomb it had hit on the side of the road), once the war started they found new roles and didnt have the time or resources to rework something that became a backbone to the end, but had they replaced it with a more advanced dive bomber (stuka was a german abbreviation for dive bomber not just the ju87) who knows what would have happened, they were working on a replacement jet powered plane to where the pilot laid down so avoid blackouts, it looked alot like the salamander (forgot the specific name). personally i think they should have just put in a big radial engine from the do.17's bombers that were taken off the line, like they did with the fokewolfe 'd-long nose' variant that thing was a beast after they put that engine in. check out the post i did on the sturmtiger- it has some great shots of stukas destroying buildings

so yeah design wise, old and nearly obsolete by end of 1930's, but
practical design usage, new uses came as the war progressed despite losing many of its original roles, as a defensive/offensive weapon this this was simply irreplaceable