The first Mac with a T2 chip was the iMac Pro 2017, and that product line was discontinued as of March 5, 2021. Does Apple still sell machines without an equivalent level of TPM?
For what it's worth, it looks like macOS tends to support hardware that's up to 7 years old[0] and macOS versions tend to stay supported for about 3 years[1].
My guess is that by 2027, all Windows and macOS releases for non-enterprise users will either require a TPM or be out of security support, and governments will start banning the latter versions from accessing the internet.
