Let's slow down on these talks of buffing Kayle
Let's remember why she's in this state in the first place. First it was full AP Kayle nuking you with Q then cleaning up with E. That got nerfed. Then it was the more on-hit style maximizing the potential of her E and that got nerfed. There actually isn't really any gameplay to Kayle. She stands back and presses buttons on you and if you dare to attempt and dive her, she presses R on herself that makes her invulnerable from any damage, which also costs zero mana and has a stupidly low cooldown.
You need to understand something, and if you play Kayle and want her stronger, understand I'm not calling you out or attacking you, you cant just buff her. it's the same with Syndra, you can't just buff them. You're going to push them back right where they were before, extremely oppressive lane bullies with incredible late game scaling. That's never good. And while Syndra can just stand for power shifts in her kit then buffs, you need to look at Kayle from an entirely different perspective.
For starters, I'd argue Kayles identity is her ult. It's a cool and unique ability and I think I'm many ways, you can work with it and keep it in her kit while still having a heathly feel to it. Her E and Q are pretty absurd, not to mention her passive. In particular, I actually like her E because it's one of the few abilities in the game that toggles a ranged auto attack. I think building around this is a good idea. Her W is lackluster and may as well not exist, they can probably honestly just remove that for something better. I don't pretend to know what to do with her overall, she's an ancient design but these are some things to take away from what I'm saying. You can't just straight up buff her.
I don't know if she's in riots scope for a rework, there are candidates in much more need. In particular, I don't think Kayle is necessarily terrible either. Minor buffs are one thing, I wouldn't mind that but again let's keep in mind why she's here on the first place. It's uncommon for older champions to be in a state such as this, as a Nasus player I realize that if a meta ever unfolds where he becomes extremely weak, straight up buffing him is a mistake. Powershifts in kits and small reworks are often the way to go with older champions and Kayle is no exception.
Just keep that in mind, that's all I'm saying y'all.

really cant over come. Yes in the lane she is annoying, and can chunk people but that's easy to solve. CALL the Jungler. Ekko would be a good example, because without flash there is almost NO way Kayle is getting away from that gank. After 6 she does get the shield but "Chunking" become less viable as the BURST champs start getting going. Even shielding herself they just have to be smart enough NOT to dive her unless they know what there doing.
she could be a pretty nasty split pusher when it comes to clearing waves. the few times I played her I would play support until the lane finished then build those and start pushing lanes. If left unchecked she could do bad things. and get worst once she could roam hard.