2 MB is, as already pointed out, already quite large. And remember: that's just one image. A page can display several, so for a screenshot-heavy post (not even a whole page with a question and multiple answers) the page-specific content can still easily approach, say, 10 MB if screenshots are around that size.

In https://meta.codidact.com/comments/thread/10095 you mention that you have a 4K screen and that your "screenshots often end up around 20 MB". I find that dubious, as for example 3840x2160 at 24bpp is about 23.7 MiB of image data. This would imply that your screenshots are often essentially imcompressible and that every pixel is equally important to convey your point.

Also, even the current limit can be a UX and to some extent accessibility issue. If I'm on mobile, 2 MB takes somewhere close to 20 seconds to download. Your "at least" level of 10 MB would take a minute and a half. Multiply that by several images on a page.

Not everyone is on a gigabit-level fiber connection.