If larian was using the Fizban's version of dragonborn, they would be well-suited for melee combat, due to the breath weapon being able to be used in place of an attack, allowing for extra attack. Dragonborn usually lend themselves well towards hybrid classes that have a mixture of spellcasting and melee, but I have also seen them used well as pure spellcasters.

I've never had an issue with dragonborn not feeling integrated, but perhaps the reason you might be feeling this way is due to the lack of them in larian's world. While it's true that dragonborn are not very populous (tymanther is a relatively small nation), they seem to be practically non-existent in this game, similar to half-orcs. The only dragonborn npc that I can actually recall seeing as a living person and not an aesthetically placed corpse is Quill Grootslang. There's probably more, but if there are, i genuinely can't recall them.

As for npc reactions, it's unlikely we were ever going to get much in this regard, npcs are far more likely to react to the presence of drow, and we've already had many players complain about the lack of acknowledgement there too.