ASIC chips can never keep up with the logarithmic increase in power required to solve the algorithms.
Do you realise that mining difficulty is a result of increased hashrate and not the other way around? Miners don't have to keep up with the difficulty, the difficulty keeps up with the miners. The only reason the power required increases is because the hashrate increases. When we run up against the physical limit and Moore's Law stops applying there won't be new generations of ASICs, so the hashrate will stop increasing exponentially, and so the difficulty will stop increasing exponentially. You have the whole causality of the situation backwards.
So why have the number of miners fallen from hundreds of people like Bob in a backroom with a PC to a few huge companies (in China) with farms of machinery? Because the hashrate has gone up so much. But why has the hashrate gone up so much? .... Chicken or egg which is first? To be honest, it does not matter, only that Bitcoin is reliant on a few (almost getting centralised) Chinese farms. We, the community, have little input, in fact zero.