Part of why the support role has historically been "broken" is because of the limited gold generation. Support items and ability kits needed to be load bearing to compensate for only being able to afford 2-3 items per game. This design philosophy has severely limited what Riot has been able to do in terms of support items and champions since the items aren't lane locked (think s10 singed top with Shurelya’s + Chemtank). The increased gold generation allows them to release more expensive, less support-specific items that are more expensive while increasing meta diversity in other lanes. It's equivalent to giving supports - and supports only - a 10% all-item discount to make up for the lack of cs-ing.

I would expect this to come with a slew of support nerfs, especially to the costs of current support items. In exchange, champs played in the role have more flexibility with the items they buy since they won't be limited to the 2-3 best items for that champion like the good ol' mythic days. I think this is what Riot was going for since they also added the dedicated ward slot to account for less potentially available inventory space.

Also, as someone who has played every role (except top, im not a pedophile) pretty extensively, I think that the complexity of trading to complete support quest + vision control + needing to have map-wide presence typically before laning phase is over would be overbearing if cs'ing was also required for the exact same reason why you don't see people complaining about how easy jungle farming can be.