hence my question do we need ranger to exist at all or is it just blind tradition at this point?
Yes and No.
The Ranger, via it's various inspirations, displays aspects that the community don't want on other classes as a base option and acts as a nexus for them. The tradition is the act of keeping the other class to their core identities and not spending any power on ranger stuff.
The question was with regard to an explicitly non-magical set of wilderness-themed abilities. I'm saying that tying those to specific character classes, rather than a separate system which characters of any class can take, has a conceptual awkwardness to it. The same way that fighters aren't the only ones capable of engaging in melee combat, it can be hard to justify why learning certain non-magical abilities is tied to a particular character class. That's why I mentioned thieves, since I recall a lot of people pointing to the idea that no one besides them could detect traps, hide in shadows, etc. as something that they had a hard time with
It was never about gating features away from other classes.
Think of it this way.
The fighter has access to every combat style. The ranger has access to some combat styles.
The fighter has access to so wilderness stuff. The ranger has access to all wilderness stuff.