Maybe I am looking at this wrong but, lets say for a minute that somehow it were even pssible to forever limit mining to CPUs (which I don't believe it is but that's another discussion)...
Wouldn't eventually pretty much the same thing happen, it would become only profitable for those with the most (and fastest) CPUs and the resources needed to support them (electricity, etc) at the lowest costs. So for the average person with one or two average computers in their house eventually would not be able to profit?
And even if there isn't specialized hardware available to those with the know-how and resources to use it, there would still be specialized setups/datacenters (like mine in my basement, lol), and enough of them, that the same end result would happen as we have now with GPUs, and will have with some other technology in the future that we might not have even considered yet.
Am I wrong in thinking that as long as there is profit to be made, there will likely be many people competing for a piece of it which will always and automatically lead to those with the skills and resources will be the ones getting the profits, regardless of any limitations of what technology can be used?
Thats pretty much correct. Although there are some nuances; for instance, an individual who already owns a (gaming) PC may not have to factor in the cost of hardware. A "professional" will have to. Same applies to electricity, an individual would only have to take in to account the marginal electricity consumption caused my mining (for the time his machine would be powered on anyway), a pro would have to take the entire power consumption in to account.
But yes, by and large, eventually mining will only be (marginally) profitable for those who can achieve the lowest cost /MH.