m68k is the equivalent of those, it's late 70s/early80s, with speeds in the low MHz range (e.g. 7.67 MHz for the version in Sega Genesis) - but I haven't seen claims of FHE having that high of a performance (e.g. sum or filter a million numbers in a second as low MHz allows you to do) but only something an order of magnitude or two slower (e.g. 13ms/core for a bit operation might be treated as comparable to a 0.077 MHz microcomputer; you can parallelize over cores but that computer parallelized over bits), so we're talking about much more than a 40-year regression of performance, as it's slower than the first 1970s microcomputers which themselves were slower than the 1960s minicomputers, so perhaps the 1950s early transistor computers?

And a from-0-to-100 gain in privacy.

Calling this a "regression" is nonsense.