I grabbed the 9700k on a whim really and hadn't heard about the frametime issues at that point even reviews at the time stated it was a solid gaming cpu, ony shortly after purchase did I notice the frame time issues and see them start to crop up on YouTube vids and it was too late by then.
I game at 3440 by 1440 on a 2080 super.
I've come into a bit of doah so wanted to sort my frametime issue out and possibly grab a 2080ti if I find one cheap enough till ampere appears which will hopefully be September/October time
if it was me i'd keep the 2080 super as thats a solid card, they should overclock well too, i'd be buying a b450 tomahawk/x570 and a 3900x.
the extra cores will help no end with multi tasking and although frame rates may be lower, frame times will be a lot more consistent with very few or none to be had. Also you'd have a upgrade path too, if you buy a 2080ti you still have the same cpu that is suffering with frame times and will likely get worse due to the more powerful gpu, it'll be a catch 22