As a support main, here is what could make the role more popular

We all know it, support is the least desired role in the game right now both in ranked and normal games, with high elo being the only exception. Now, while many players tend to dismiss this with the fact that most players want "make plays" and see big numbers in their damage count, I honestly think it's more related to how the role plays significantly different than any other role, and how the handicaps you have to play with affect the enjoyment of the role in a subtle way that make players unwilling to play it just for the fun. I don't think that Riot should enhance support's power level, but there are certain areas that could be improved without directly buffing them. What should be done instead is curbing down the unnecessary burdens supports have to play with and that don't add meaningful depth and strategy to the game. In short, what I propose is not to make support a stronger role, but to tone down those unfun mechanics that players aren't comfortable with when coming from lane or jungle experience.

1. Enhance the inventory efficiency.
   While most games end without 6 complete items in the support inventory, supports still find themselves in a tight spot whenever there is a stealth champion in the enemy team because, coupled with sightstone, those are 2 slots spent on vision that, while helpful, doesn't help you when the inevitable fight start. Having a vision ward slot, or more upgrades for Sightstone would help supports in purchasing health, resistances, or component items even while contributing to vision, thus staying relevant as utility and presence in all stages of the game. Now, while supports tend to not synergize that well with items, that's just another reason to add another layer of "punishment" to the player in that role by limiting his or her inventory to three slots+boots. While your teamfight doesn't really change if that bard has a cloth armor, it feels better to not be limited in your itemizations, making supporting more enjoyable.

2. Ease the experience burden on warding.
   on top of sharing a lane, supports also have to roam to other lanes or the jungle to place wards. This increases the experience gap in levels between them and solo laners, exacerbating the intended role weakness more than necessary. Supports shouldn't outlevel others, of course, as that would make support reliant on levels, like tanks, even stronger, but they should'nt lag as hard behind as they currently do.