May be you need for some reason you only can know. We do not know what Canon needs! Unless you work for Canon of course) Also an APS-C high frame rate is used for birding mostly and sports (maybe). In these cases EVFs FAIL to perform and spend battery A LOT! So the oposite seems more reasonable: Mirrorless Lower end APS-C cameras not Higher End ones.Canon should keep making the 77D or 80D but the 7DIII should be an Eos-R camera. Canon need to start moving customers to mirrorless. An APS-C high frame rate , silent shutter , good focusing system , two cards would help push lens sales.
Then also have some entry level APS-C mirrorless Cameras and drop the M series which no longer have a real future.