Pink wards for junglers

Currently G4 jg here.

I’m having a bit of a dilemma. Watching YouTubers, high elo players, coaches, etc., I’ve seen that many of them instruct their watchers or their students to “not leave the base without a pink ward”. High elo players that I follow (like Broxah, Velja, or Kaido) apply this. They most of the time have a pink ward in their items.

Now the start of the dilemma. Two days ago, a friend of mine (mid laner D2) invited me to play with his friends some custom games; it went well, we won the Bo3 and I kept playing for a while with them. However, the guy that was “coaching” us told me after every game to “stop wasting resources and to not buy pinks”. I thought it was because we were a “coordinated” team and the supp had this as his main responsibility; but he said that for a jungler that doesn’t actively use wards (like Lee Sin or Jax), buying wards is just pointless. I was the lowest ranked player there, so I shut it and did as requested.

I can’t leave things behind easily, so I got a coaching session next day (yesterday). In my first recall, I did my normal thing: switch to oracle and buy a pink ward; the guy just kind of yelled a big NO and told me to undo the pink. He said “you don’t need it”. We had a conversation about it and it arrived to the same conclusion I was given before. Kind of wasted money there, I was looking for a different approach lol.

Nowadays I’m sooooo used to always have a pink ward, till the point that I tend to back off if I don’t have one to confirm that an objective is safe or not, or just to take control of an area and make a play.

HELP: High elo players out there (at least higher than me or more experienced than me), what do you guys think? Am I “wasting” resources with the pinks? How can I take vision control of areas without one?

Looking forward to seeing your responses.

Thanks a lot!!