TTL-13/14/15 fighters are probably just armored wedges with gravatic controls. No need for an airframe. If you get hit hard enough to damage your gravitics, you likely are not going to need to be concerned about any sort of glide path, much likely anything else.

Both atmospheric and space are optimizing for low surface area (lighter armor) given enough to mount weapons and sensors. Wedge and flattened sphere’s seem a great tradeoff.

Also, Space optimized fighters are likely to be as armored as tanks, and as well armed. Well, at least CT/MT types. And if you want your pilots to be able to have somewhat normal kids, having them well armored and/or shielded is essential.