Some of the weirdness is academia has a fairly extreme demographic contraction from the Boomer retirement wave because not only was it a i) big cohort that ii) worked later in our industry but iii) structural changes shifted the share of TT jobs in the field, altering career dynamics.

Yeah that’s what someone else told me. As some Boomers retire, subsequent groups aren’t nearly as large, so “senior” may trend more mid-career.

So, yeah, you can be a "senior" as an elder Millennial/young Xer in some departments as a result, I think.