Vision? The very thing that helps keep you commonly updated on gank attempts, JG objectives, and roaming attempts? Actually I do as in the low elos I'm usually the only one warding anything. However the upgrade requires you to spend 800g which can be used on something else as you already have 4 wards every back as is.
I understand the importance, you're the one here that doesn't seem to understand the importance of building tanky or to improve healing as a support, or damage as an ADC or any other role.
Besides with
and
I can have 4 wards I can place at once on the map for only 1050 gold vs 1600 gold for
which offers no stronger benefit til late game.