the only reason chia doesn't have specialized hardware that crowds out all commodity hardware is because no one cares about chia. the reason that bitcoin has highly specialized asics is because it is the progenitor and center of the entire cryptocurrency ecosystem and has been for over a decade. also proof of space is no better than proof of work at scale. it will ultimately have very similar consequences.
There is no such thing as specialized hardware for Chia farming. If you manage to pull that off then congratulations, you have created a bigger hard drive.
the history of cryptocurrency is a history of projects making that exact claim and being proven wrong over and over again, but surely this time is different.
I have in fact not heard that specific claim much. There was the whole "ASIC-resitance" trend and the projects that did care about it (like Monero) tend to be right in their claims. Ethereum is still to a large extent mined on consumer-grade GPUs.
There is not even any consensus on if this is desirable for PoW chains.
Bitcoin requires custom hardware. Chia does not - you can use an ordinary hard drive and run a full node on a Raspberry Pi.