You seem to be confused about some relevant facts in your Canon time-line.

1, The FL lenses were / are fully compatible on FD-mount bodies. Did you actually drive off the road to success as far back as 1971?

2, The EF-S mount really doesn't rise to the level of a mount change. You're probably familiar with Nikon's DX lenses and cameras, similarly the EF-S mount is specific to cropped EOS bodies, a line of cameras that also can use every EF-mount lens ever.

3, The EF-M mount is very specific to a line of cropped mirrorless bodies. Both EF and EF-S lenses are fully compatible with these cameras via an EF-M adapter.

4, You've probably heard now about Nikon's mirrorless Z-mount? You mentioned it. That's the RF mount for Canon EOS full-frame mirrorless. What you probably don't know is that every EF lens ever is fully compatible with the RF cameras, via the Canon adapter. None of the EF / EF-S lenses are downgraded to manual. N O N E. None of the EF / EF-S lenses operate differently on different mirrorless cameras. None, nil, nada, zero, zilch. Maybe when you started this post to pat yourself on the back, you had a small nagging fear EOS technology has displaced Nikon as the upwardly compatible digital platform?

5, For all those EOS mirrorless options, now the age-old R, FL and FD lenses are ready to live on as manual focus lenses on digital mirrorless cameras with the appropriate adapter. So, if you'd gone with Canon way back when and stayed, all that Canon technology can be integrated onto a single digital mirrorless platform.

Falsely denigrating the global leader seems like an odd way to justify staying with the now #3 brand.