There is an obsession regarding high megapixel cameras. A parellel in cars would be the Dodge Viper, which had a 1000 horsepower engine but bad handling on the road. Megapixels is only one aspect of sensors. Far more important is dynamic range, color sensitivity response, rendition, ability to raise shadows in post, etc. The higher the megapixel count, the more difficult to excel in these other areas. Let alone the ability to handhold a camera without shake, which becomes increasingly difficult with higher megapixels. Canon, even with the latest generation sensors, has had lower dynamic range and particularly the ability to raise shadows in post without banding and noise. The same applies to lenses like Sigma Art with the obsession on sharpness. Only one aspect of a lens performance. The older lenses had a 3d quality and rendition that the newer lenses don’t. It is called character. Newer lenses are sterile and flat. What is it with the compulsion to have ultra sharpness and minute detail at the expenses of more important qualities?
Well, as technology progresses, it can address the weaknesses as you describe.
The last Vipers to come out, had some really good electronic help on the suspension, etc...so as to keep the car on the road and it wasn't in as much danger of the driver losing control.
Of course you could turn those safety measures of if you wanted a bit of the raw power to toy with....
The Fuji GFX100 line has shown that a large sensor with high MP count....paired with IBIS, you can indeed hand hold at MUCH slower shutter speeds than you'd expect and come out with pristine images.
IMHO, the limitation with higher and higher MP is trying to stuff them into a FF sensor, rather than enlarging the sensor.
Larger sensors, IBIS and who knows what in the future, will allow ease in higher MP that are effective.
As for lenses, I do agree with you. Today's lenses are getting towards perfection....but they also have what many call a "clinical" quality.
One of the main things I like about modern mirrorless cameras is the ability to readily adapt the older, manual lenses that have character to your modern digital camera and use a bit of that 3D or bokeh magic you just don't get with modern lenses.
Sure they are full manual, but with digital focus adjust, there's really no problem catching focus with full manual lenses. Hell, I can even do it with my bad eyesight.
Just my $0.02,
cayenne