Before the release of Spelunky, the same thing you say about potion systems or keybindings could be said about permadeath. Mostly all commercial roguelike attempts made permadeath an optional thing. It could be also argued that what the "games with roguelike elements" do is not the same thing as roguelike permadeath.

You never know what the future will bring. Maybe someone will create a game that is definitely not a literal roguelike (e.g., a platformer) and that is definitely not a randomized permadeath game (e.g., a static metroidvania) but still have these minor roguelike features: non-modality, unknown potion systems (if that even makes sense without randomization and permadeath), complex keybindings (I am actually quite annoyed by how some metroidvanias have tons of abilities but it is hard to use them because of their streamlined interface, so roguelike-style keybindings could help), community development, character graphics, etc.

Also while potion systems or complex keybindings are rare in new games, lots of people are playing DCSS or other games featuring them, so they still live.