Actually - that was easier than I anticipated - I've tested some settings for increasing the size of images.
Here's the thing - Modern cameras on smartphones take extremely high resolution photos, at a quality suitable for printing - far higher than necessary for it to look good when viewing in a browser. That high resolution makes the files very large.
It is important for a few reasons to try and keep the overall size of all attachments to a reasonable level - we've got plenty of headroom at the moment, but it can build up really quickly, particularly these days if we're storing images at the native resolution of most smartphones (something that wasn't really a problem when this forum was first started, as smartphones were barely a thing, and the cameras on them were poor).
However - it's true that it's a PITA having to downscaling an image before we upload it, so the 2M limit absolutely feels unreasonable.
So - what I've just done is configured it with a really high upload limit, meaning that you can upload images up to 32MB, however - before the image is stored as an attachment, it will be automatically downsampled to a lower resolution (a maximum of 1500 pixels in either the x- or y- dimension, maintaining the aspect ratio).
That way, we can have the convenience of not being restricted on uploads, and use the server itself to do it's own housekeeping and keep things nice and efficient.
That's active now - so do feel free to try it out, and let me know what you think. I'm expecting that for most purposes we won't be able to tell the difference, and for those occasions that print-quality images do need to be stored for some reason, perhaps an external hosting source might be able to be used (imgbb.com, imgur, etc)