I've been there. First step Z590 & 10th, then fully went to Z590 & 11900KF, although it's 2021 and had to go from 10 cores to 8 cores 🙂
Parity errors might be gone, and some stated that 11th is more stable in games, others not... In any case, it matters A LOT the games you play, in few indeed performance and stability is improved. To be honest, in the games I played (AC Creed games, Watch Dogs Legion, RDR2, Cyberpunk 2077, last two Tomb Raider games) performance is a lot worse using a 11th, the lows decreased about up to 15fps using the 11th, and that matters a lot when you're going from 80-ish to 60-65 (1440p).
PCIE 4.0 did not bring any improvements in daily and gaming use for my 980 Pro and KP 3090.
Yeah, 11th might be better for DDR4 in some cases, some stuff now is really working, but instead you will have another sh*tshow to live 🙂 - I think there are threads with issues more than any generation so far for 11th and crappy Z590 (which is already a crap, but also FUBAR by Asus)
Had a crappy Apex XIII, which is the pinnacle of Asus's incompetence so far - board design itself, BIOS, support etc. which after more than three months of pain I decided it to scrap it (thanks to Asus's marvelous warranty and RMA policies I basically flushed down to the toilet 500 Euros), in the end I went back to XII and 10900K.
Next one it won't be Asus for sure.
if still need a back-up, grab another 10900K will do...
worst case scenario Intel will replace your stuff, it won't be like there will be nowhere to find
and yeah, we'll keep for a while the gear we have now, at least Alder is a must skip step =))
DDR5, PCIe 5 and other uncharted territories, that would be a nice $#!show to watch =))