F-Zero also likely suffers from the fact that it probably doesn't have someone championing it right now as a game or series they'd like to make a new entry in. We got a brand new Famicom Detective Game after about three decades and that series was given a new chance at life in part because there was someone that wanted to revisit it. We did get F-Zero 99 which was a sign of life for the series even if it again avoids the 3D of it all. I do think that has helped show there would be interest in a game. It's just a matter of when someone at Nintendo would want to retackle it. Kid Icarus seemed dead until Sakurai decided he wanted to make an entry for it and now he's bringing back Kirby's Air Ride. All of that tells me that F-Zero isn't dead with Nintendo. There will probably be a new game for it at some point. It just depends when someone will finally be willing to decide that's what they want to make.
Or else Nintendo finally does farm it out again. Keep in mind that F-Zero GX was really more a Sega game than Nintendo. Even then, F-Zero wasn't something that creatives inside Nintendo wanted to tackle. According to Nagoshi, who was the person who really developed GX, Nintendo was highly impressed with what Amusement Vision made which you can take a few ways. Either they didn't think another company could make a game at the Nintendo sort of level or they didn't see F-Zero as a big priority and were surprised to see what heights an F-Zero game could reach. They've said things about not knowing what else they could do to move the series forward after GX. Considering Nintendo just went back to 2D for the series twice more on the GBA, they just don't seem to want to make the jump to 3D internally aside from F-Zero X. If GX didn't exist, I wonder how many people would be asking for a new F-Zero game still or if we'd have just seen it as an antiquated old style of racing game and a minor part of Nintendo's history like Mach Rider or Excitebike. Don't hear people wondering when Nintendo will finally return to the Excitebike series. But since Nintendo didn't design GX, it leaves the series in an odd situation with the company. If Nintendo finally decides to take another crack at the series internally, it could end up looking rather different than expected. Sort of like how Donkey Kong Jungle Beat and now Donkey Kong Bananza are willing to take DK in different directions internally compared to what's been done by Rare and Retro with the DKC series and fan expectations of what elements make a DK game.
Nintendo can point to sales as a safe way out of not making a new F-Zero entry but, I think based on the history, they just don't really know what they want to do with the series or seem to see it as a 3D series. If Nintendo was going to stick by GameCube sales as justification for decisions then we wouldn't have seen Luigi's Mansion 2 or a new Kirby Air Ride game. Perhaps Mario Kart is also a factor with it taking up all their ideas and focus so that another 3D racer seems redundant. (However, considering the company has also got multiple series known for 2D platforming games, I don't think redundancy is that big an issue.) Still, if Air Ride can return then I do think we finally see another 3D F-Zero and I even think we see it in the next five years on Switch 2. The big question is how many franchises can Nintendo keep juggling? In the past decade, they finally got Fire Emblem to take off big. Pikmin 4 has helped boost that series power and justified making a Pikmin 5 and that there will be demand for it. Animal Crossing hit huge numbers with Switch. You've got the beasts of Mario and Zelda that need to keep churning out entries. Metroid Prime 4 may determine what Retro's making for the next few years. The future of Smash Bros. is currently in question of how to follow up Ultimate and who may do it if Sakurai really is stepping away from the series. If DK Bananza is a big hit, is EAD going to try and juggle Mario and DK games going foward? If F-Zero does come along and turns out to be a success both in sales and with fans then that will cause demand for another future entry. That's why farming it out is likely how we'll see a new entry. Find a studio willing to make the entries for that series sort of like Next Level Games has become the Luigi's Mansion and Mario Striker's dev. Pokemon company handles the Pokemon games. HAL handles Kirby. Retro and Mercury Studios have got Metroid duty. Monolith Soft has Xenoblade along with their assistance in Zelda. Mario Party by Hudson aka NDcube aka Nintendo Cube. Fire Emblem and Paper Mario are Intelligent Systems. They'd probably want to find a company to try it out and if successful then have them keep making more entries.