I've been playing some matches as a support more recently and noticed a big gap between when it comes to all support and the newer addition, namely Pyke.
I'm not currently interested in playing as a support main as I have been before, but when I played against this "support" I started to notice many things that set him high above all other supports.
Specifically his arsenal of spells:
Hook which deals too much dmg as a supp and has a very small CD
Invisibility + movement buff + regeneration, no support has that kind of spell that would combine that much stuff into one thing, usually supports have no escapes from engages apart from very few that don't have it this strong.
His dash + stun with a small CD, is also another tool that is in many ways much better than that of other supps. It's theoretically Taric's E with much better handling and a dash to it.
His R is a Darius R except if Darius R could somehow hit more than 1 target at a time and if it dealt that dmg without any kind of foreplay. Also it's the only ult that gives the support the option to be as fed as his other teammates while not giving anything up for it.
In my opinion these spells are pretty much the combination of all the good spells from all supps and some other champs as well, mixed into one champ, giving him no disadvantages at all.
The perfect support champ that stands above all others. Having the ability to serve as a hooker, stunner, damage or a possible tank.
Let's compare it to others:
Nami has CD and heal/buff. If engaged she has almost no escape except landing her CD and run with the small movement buff from passive. Remember she has nowhere near as much dmg though as Pyke and is more squishy.
Tresh has Hook, Lantern, Knockup and a slow. He provides option for escape of others while having no escape option himself as most of his spells are about engage and keeping enemies away from others but not himself. Overall he is not the best tank and has also nowhere near the dmg as Pyke.
I could go through all supps but I think you get the point now. In my opinion Pyke should have at least 2 of his spells changed in order for him to be "balanced" with other supps.