I’ve been playing the game since about September of last year and I got my 4 best sets up to S cards like a couple months ago? It wasn’t something I had been trying to do from the start though so I’d say it definitely took me a few months but that’s bc I wasn’t actively hardcore powering up my cards and a lot of them came gradually. So overall I’d say getting matching sets up to S/R rank takes at least a few weeks or months to do if you’re not spending a lot of time playing the game daily. I’ve gotten a lot of cards just from events (my SJ-M set is all S/R bc of events they love to give me super junior) so a lot of it is also lucky circumastances ;3;