Actually, it’s strange no one has thought about it before!
The Ford F-150 Fastback is actually a mod but it’s now a commercially available mod, due to the interest people have shown in the look. It’s basically the same thing that the fastback design did for muscle cars in the 60s! (although actually fastbacks were popular in the 50s, too, and even date back to the 1930s, although the 30s ‘fastbacks’ don’t really give the same impression because they’re just a part of the overall rounded body style of the time.) It’s that sloped smooth yet powerful look that can be added to any car… or truck now!
The F-150 Fastback trend seems to have really started with a guy who had modded his own F150 this way, and a photo of his truck caught the attention of netizen Ford drivers. Then The Drive decided they wanted to actually make it a real thing for any consumer who wants it! There’s a company called Michigan Vehicle Solutions that has already been doing F150s Fastback mods, but The Drive seems interested in pushing this thing (in terms of just becoming popular enough that it’s viable in a business sense) so that Ford might just start making their own, too!