I struggle to see the cons of ekko.

Gets out bursted by most other assassins:

Q is easily avoidable, second half of it more so.

W is extremely slow and highly telegraphed.

R is the most telegraphed ability in the game, anyone who stands on it should have their computer blow up irl.

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He got buffed again though.

That buff was a cooldown to his E early game, which is a noob trap to make him go oom. That buff only made his lane a little safer in case he gets ganked after using his E.

he got nerfed into oblivion.

He is afraid of officer Caitlyn and officer vi.

His damage early isn't great and forces him to play passively until he gets a couple of items.

His W is easily telegraphed and is hard to land unless he casts it out of your vision or you're already CC'ed.

You can outplay every single ability in his kit bar his E.

He has to get in your face to deal damage. He cannot poke you from afar unless you walk into his Q.

His burst isn't as high as some assassins.

Q is easy to dodge. W takes forever to activate.

That said, Ekko is the only champion that can TP gank, get a kill press R and appear back in his lane.

You must be trying really hard to ignore them then because they're about as obvious as the cocaine mark across his face.