We need a good look at Mages

There seems to be an issue with them, particularly the design around them and their itemization. It's not a simple matter of "Mages are underpowered", they are not, except perhaps on individual levels. It's the overall that distinctly has design patterns that are negative.

The first and most obvious issue starts with scaling. AP doesn't scale into auto-attacks, however this means that they require more use of their resources (particularly mana-dependant ones) to endure and maintain a damage presence in a game. They do not have as reliable tools to maintain their mana or other resources as some other classes do and with elevated costs compare poorly over extended periods. Side note would be mentioning Nashor's buff, where mages literally CANNOT DEAL WITH MINIONS. (Spells don't damage, attacks do not scale.)

The second issue is itemization. Many mage items are primarily stat-sticks and secondarily a counter-meta item. There appears to be distinctly less variety to what a mage can/should build on the overall. With reference back to the resource issue, their first priority is bridging that resource gap. This means they lack the power-focus that other champs may not have. If they bridge that item gap early enough, they often become power-houses of damage that scale well into mid to late game.

The third issue is priorities, goals and identity. While this varies from champion to champion in how they prioritize. (For example TF does better with multi-lane pressure and ganks, while Heim's bunkering down makes him more of a single-lane powerhouse.) The overall goals of the class/role is not defined well. They have too many "tasks" with no core ones, which is very detrimental to their identity.

So. The temporary band-aid fix to all of these would be introducing and reworking items that allow them to bridge the first two issues. Creating interesting variety in their itemization would allow them to have that reliable choice. However, this can and has come full circle. If I wanted an item that lets a mage be more of a lane-pushing power-house, Banner of Command was the go-to. Now it's not. It's a distinctive choice to consistently shift the items that give mages variety away from their use, rather than try and maintain them as items a mage can use. It's a bad choice. It's difficult to say there really is an obvious fix, because there isn't. It is also important for steps to be taken toward making the overall less negative so the class doesn't suffer in the longer run and many changes do not feel like they reflect that.