Remember when CDR was a relatively difficult stat to build? And the games skill cap wasn't so low..
And it was primarily used for tanks/utility mages and now it's become a staple for every class to hit 30-40% CDR
Tanks get CDR from damage now with IBG and that's a terrible idea
ADCs get CDR galore through just about anything they build, some still don't need it tho
Mages will have CDR galore in exchange for weaker AP (which is a buff overall because more spammable spells = more damage) once the Mage rework hits
Supports getting CDR was fine, even tanky supports because they don't build damage items and abuse grasp
Basically, CDR was a stat you had to commit to and sacrifice some things to obtain. You'd likely lose out on up front damage because you're AP/AD would be lower since the items you'd build would be low AP/CDR items or tank CDR items. That's all out the window now because everyone builds it and gets 30-40% making skills more spammable. What does this do? It diminishes skill cap because you can spam spells more, suddenly the game is more forgiving because missing skill shots won't matter when they're on such low cool downs. Tanks can perma tank still but because of damage/CDR items like IBG, they can kill your carries with grasp procs + IBG procs and sunfire with extremely low CD spammable spells with decent base damages.
That's the biggest problem with this game right now and has been for a long time. You continue to move into a direction that makes this game easier to play and skill matter less and less. As long as you're playing the most obnoxious face roll crap, it doesn't matter how poorly you do because global gold is so high, towers are so easy to take, death timers are so long so early that even the largest lead can be lost on one fight because of what you stand to lose in such a short time. This makes easy to play, OP shit even more oppressively good because typically anything OP will be far more forgiving, especially tanks and ADCs with all the survivability they have right now that they ever should've had.
You've spent so much time trying to make everyone feel like they matter when they always did matter but they couldn't accept that their role had limitations because they're some whiner who blamed the game for their lack of skill. Every role has a limitation, as it should, but with each change you make with everything you're making that less and less true. You're blurring those lines where mages go and support and shit on everything and force traditional supports at. Tanks don't carry through zone control and CC/initiation and damage soaking, they simply kill your back line. Everything traditionally squishy and easy to kill is building steraks, Mercurials, maw, etc. These are items that were never made for squishy champions to damage soak and survive ridiculous amounts of burst with, they were designed for fighters but for some unknown reason, riot won't take the simplest, easiest solution and make them melee only (except mercurials, that item is a fucking joke and should have never been given all the stats it was given).
This was supposed to be about CDR being too easy to obtain but in general this games skill cap has just been taken behind the woodshed and beaten down. And that's one of the many things that has made this game less fun and the idea of quitting becomes more appealing everyday.