You're right that mana isn't exactly in the best state, but I think the situation's improved drastically, not worsened. For all the complaints people make against the updated
, I think it's good that we no longer have an item that single-handedly makes mana costs irrelevant. Every champion with a cost to their abilities, whether it be mana, energy, health or any other resource, should have meaningful costs at all levels.
As for mana itself, I think the main problem is that it's just not fun to itemize for. It doesn't really contribute to gameplay (unlike mana regen, which allows for more frequent spellcasts), and unless you're
or
you don't really feel more powerful for building it. Even items that do convert mana into other stats and bonuses, such as
or
, don't really inject a feeling of power or fun into the stat. Mana is seen as a problem players try to eliminate through items, rather than a cool system for gating abilities and granting unique strengths, and that needs to change.
A little while back, ricklessabandon tested out a few experimental changes to Muramana that had a "power-up coin" mechanic, where the active let you spend mana in order to gain a massive attack speed boost and true damage on-hit, and could be used multiple times in succession for greater rewards (and greater costs). While the implementation had a few problems, I think the idea behind it could be a potentially awesome way of making mana itemization rich with gameplay.