The proof is really in the fact that it is still happening. Mining must still be financially viable or else people would pull the plug because otherwise they are acting irrationally (or derive benefit from continuing the bitcoin fight at their own detriment, but that is hard to quantify). Maybe for small scale home miners you are priced out of the market.
this I agree with. and about small scale home miners I have to say most of them won't go out of the mining market because as a small scale miner you don't have such a high cost and you don't need to cover those costs by selling bitcoin as a result many of them can just mine and hold bitcoin while paying their bills from pocket. something like an investment.
additionally there is always improvement in mining scene. for example Japan is now producing better mining chips which they claim is going to top Bitmain
https://bitnewstoday.com/news/technology/gmo-introduces-new-mining-chip-ceo-reportedly-vows/What may cause the lag is the time taken in the small scale miners' Asic orders and the time taken to set up their equipment. By the time they start mining, the market has already crashed. Haha.