3900x 12 core 9900k 8 core
3900x in single core tests like cinebench r20 with slower cpu has almost/better than 9900k score
for the price now, a 3900x with X570 motherboard makes more sense for 99% of buyers I would buy one today (own a 9900k myself)
you get more features and a more modern cpu for the same price, Ryzen isn't as fast for pure gaming but if you don't have a 1080p 120+Hz monitor and really care about having 100+fps all the time it's not important
you cannot compare other countries prices with switzerland especially the US, US price are only for US Canadians pay more than swiss, australia way more than swiss, france too 3900x digitec price is totally ok