If you could fire turtle shells at your opponents in Gran Turismo I wouldn't consider that a racing game either. You may as well add GTA to your list of "racing" games since like NFS it centers around evading the police in car chases and like Mario Kart you can fire at your opponents vehicles.
If you want to have the opinion that anything with weapons or obstacles isn't a racing game, best of luck to you. You're wrong, but nobody can stop you from being wrong.You're not going to change my opinion on this one. If there are "obstacles" like banana peels and cop cars it's not a racing game. Racing games are about out racing your opponent. Those games belong in the same category as Twist Metal. Car combat.
So there is some hope for this point I believe, maybe just a little, I have nothing concrete but here's my thinking looking back at the main games.Now you've hitched yourself to a system that actively reduces how much you can actually make a game next gen, and considering how long Polyphony takes to develop games, the first true 'next gen' GT game on PS5 might very likely be 75% of the way through the generation.