[t0bia_s]

Cameras made after 2016 are so good in terms of image quality that you will not see any improvement in newer cameras. So upgrading is reasonable option only for those, who need better functionality, which majority of amateurs don't need.

[stephen_g]

It depends for what. There are still ways to go with video, but mostly only for people who care to colour grade their footage. I expect a significant proportion of people now are buying mirrorless cameras now almost entirely to shoot video so I expect it is a major consideration. Things like in-camera 10-bit raw video recording which is still fairly rare. Probably mirrorless cameras will start being able to shoot 5K or 6K too, which is useful (for reframing by cropping in, otherwise downscaling to increase visual quality).

[t0bia_s]

It is pointless for casual consumers and professionals usually use cameras dedicated for video (Arri, RED), not hybrid camera.

Sure, there is specific group of enthusiastic folks on youtube that promote products consumed... by youtubers I guess?