This is exactly the problem, demand far outstrips supply so they can get away with anything they want to and still have full order books. It has been this way since ASICs first came out and all the manufacturers have been the same. Until there is more competition in the ASIC miner market things are very unlikely to change.
It's inevitable since they are the only market maker for ASICs and be able to driving bcash price to increase as well.
I'm wondering about the news of new competitor from Japan that create 7nm chips for bitcoin mining, people really waiting for professional companies to handle this business, not just monopolized by Bitmain which can sell some broken ASICs, literally some scraps.
https://news.bitcoin.com/japans-internet-giant-gmo-launching-bitcoin-mining-with-7nm-chips/
Japan’s leading internet conglomerate and bitcoin exchange operator GMO has announced that it is expanding into the businesses of bitcoin mining and chip manufacturing. The company revealed plans to produce and sell 7nm semiconductor chips and run a mining facility in Northern Europe.