I dont mind supports being very powerful, but they need to be less reliable in exchange

Every other class (minus ADCs to a large extent) has generally become less reliable.

Tanks, as frustrating as they are, actually lost a decent amount of reliability. Maokai's R isn't 100% guaranteed useful like it used to be, rammus can be hard CCd out of his powerball, ornn is almost all skillshots even though his numbers got super overtuned the last couple patches, sion is in the same situation as ornn except he's numerically broken right now, etc.

Assassins, do I even need to say anything? They've all become less reliable, although rengar got reverted.

Bruisers are quite a bit less reliable overall. New bruiser designs like camille have a lot of counterplay built in, and reworked bruisers like darius lost some of their really cheesy stuff (instant decimate).

Mages have always been generally unreliable as they have always been the class with the most skillshots, and those that are reliable like malzahar have always been cancer.

But then we get to supports... And that's where you see all the point and click still left in the game. Just look at lulu, she's guaranteed useful if she presses all the buttons on her ADC (her Q is her only skillshot). Just look at janna's she's guaranteed useful if she shields her ADC and presses R to heal them. Kench is guaranteed useful if he presses W on his adc every time they get caught.

In all fairness, the more offensive oriented supports tend to not be as bad as the defensive ones, as the offensives ones also tend to be less reliable.

The worst offenders are support items. They're all guaranteed useful. Locket? just click on it. ardent? Just shield your adc (always a point n click sometimes its just a click you dont even have to point). This new creepy ghost item thingy? Just click it for ghosts to autonomously chase people down. Knights vow? point n click for it to take effect. Mikaels is point n click, though you can argue that timing takes skill in itself which I can respect.

Redemption is kind of a skillshot, but the area is so goddamn large that the aiming part is generally negligible.

tl;dr if defensive point and click heavy supports are going to be very powerful, then they need to lose some reliability and get more skill expression.