it really should have been a EF-22/2.0 STM pancake. Not EF-S. Not 24mm. Not f/2.8.
I agree with your point of view and I would even go further.
It would have been nice for low light purpose (use in a church for example) to have EF 20mm f/1.8 STM. It would be interesting for both APS-C and FF
A large aperture ("f-stop") is no longer a requirement for low-light photography, in the same way that it was back in the days of film or sub-ISO800 sensors. Plus, if you want shallow DoF, then a 24mm lens is anyway not the lens to use.