The thing is, Tiefling is a specific assembly of these tropes that would have a different connotation than another character from another race doing the same things. The Tiefling's inherent association to the occult and demonology provides major context that varies them from, say, a Dwarves Dwarf hunter.Outcast is one of the most basic tropes that could be absolutely applied to any race you can imagine if that race is tightly codified.
Hunter of own kind? Bounty Hunters? I'm stunned you would think this is in any way race specific.
Atoner. Absolutely any race can do something which later generations feel the need to atone for. From betraying ones family or clan, offending ones gods, or perpetrating some kind of evil. The list could be endless, literally.
Bael Turath - Yes, the major cultural hook for the change to 4e style is important, I'll give you that. However hoping for ones lost heritage to return to prominence? Thats a Dwarf Trope if I have ever seen one.
Devilish Heritage - Any fiend planetouched (and there are more than Human based ones) could do this. Its not a cultural issue at all?
Rivalry with Dragonborn - Yes, you are looking at a 4e setting specific hook, but...that doesnt mean I'm wrong. Any race can do this.
Big Horns - You may be kidding, but that still is the major call out here, especially if you are not looking at it from a 4e setting specific POV.
I don't like "racial rough-equivalency" arguments because it's like saying "Why play a Cleric when you can just be a Wizard?" or "Why should Ranger be a class if I can do something similar as a Fighter?" After all, both classes may wind up in similar places, but they're built on different foundations. Be they mechanic, thematic, narrative, or otherwise.
Tiefling is one of a few avenues to engaging with those listed tropes-- it's not the only road there, but it certainly isn't the same one as the rest, and that's what leads people to choose it specifically. With that said, I think that Tiefling could lean into their lore a little more in order to be more meaningfully distinct.