I have used some of the alternative components and I agree with whoever above stated that Shimano is built to a higher tandard, but it's not by much. I find I can get 4 chains to a Shimano cassette, maybe about 12,000 kms. With a Sunrace cassette, I find that chains #1 & #2 are fine, but my the time you replace chain #3 you get skip when you apply power, and so you need to adjust your take-offs etc for a few 100 kms, until the chain wears in a bit and things play together a little more nicely. Microshift Acolyte, Advent and Advent X all seem to be okay (although I've only ridden Advent briefly), but the 7 speed microshift trigger shifters on my kid's bike are/were garbage. I scored some used Shimano Tourney shifters from an LBS for a few dollars that are made to a much higher standard (and that's saying something, I mean, we're talking about Tourney here...).
Still, right now there seems to be a lot of grey-market Shimano stuff available on Aliexpress. It seems real? I know a guy who rides it, I examined it really carefully and couldn't see anything that immediately screamed fake. I've also heard from a Taichung-based industry guy that there's a lot of "earmarked for OEM but diverted" stuff that finds its way onto that site. That said, obviously there's a bunch of fake stuff on Aliexpress, but you'd think that they'd be hard at work faking 1x12 XTR, rather than 2x10 Deore? I'm quite interested in some of the Taianese/Mainland Chinese alternative componentry, as well as that grey market brand name stuff, because you're not going to impoverish yourself trying it out.