Honestly, bitmain these days were getting worse because the quality of their miners compared before is different.
It's mass production nowadays. The only thing that matters for them is pushing out as much hardware as possible, and that obviously doesn't allow them to maintain high quality standards. I actually expect it to get worse due to the new competitors that will flood the market with the same quality (if not better) hardware, but at lower prices. Bitmain will have to follow with lowering their prices, and that will again mean lower overall quality.
I know it's the most famous mining company.
Actually, it is the most infamous mining/crypto related business in this market. People have no other option than to use them due to their cartel position, but it won't take long for this to change. It's just a matter of time.