You guys seem to be missing the point with these big role updates

Just like the Marksmen update, the point of the Mage update isn't just to add or take away strength from the role, the point of it is to diversify the role. They're trying to make it so there's a large difference in how you play depending on what champion you pick, just like the Marksmen update, and make picking a mage a more meaningful decision than 'We have four AD champions we need AP'.

As a mage player, I don't even mind the way they're going about it. The items are losing AP, but they're also going down in cost and gaining other stats and passives. On top of that, I forget who it was, but one of the reds said they were going to add about a thousand gold worth of stats onto some of the items. As for mana being a more favorable stat for mages: That's ALREADY a thing. Would you rather have the mana ROA gives or the mana regen that Morellos does? Hands down, ROA. You get Morellos for the CDR. There's a reason mana extensive champions like Swain, Anivia, Kass, etc opt for mana over mana regen.

Everyone sees lower AP on items and they flip shit saying how bad they are now, but they refuse to see the buffs. Everyone sees mana regen changes and they flip out that mages are getting meaningful trade offs. Saying dumb shit like 'Marksmen and AD assassins have no trade offs!' Hell yea they do. You'll notice they're usually only killing people off one at a time and don't really provide CC or utility, sure there's some outliers like Ashe or whatever, but for the most part the person holding the enemy team down and chunking them all for half their health isn't your ADC or AD assassin, it's your mage.

TL;DR: Every role has advantages and disadvantages. Every role has trade offs. The mage update, just like the marksmen update is to accentuate those advantages, disadvantages, and trade offs.