Often enough, especially in these days of higher resolution, cropping is now
more useful, not less. For example, consider the the image
from your post here (the second one, from you, not the one quoted above it). The key point there is whether or not the enemy in the sight is pulsed; this enemy is just a few millimeters in size in the image in browser window on my screen (below left). Cropping down to the portion in question displays the key part at full size in the forum post (below centre). This is from a screenshot at 1080p; had this been from my PC it would have been a 1440p screenshot and the resize would have made the portion in question even smaller when embedded in the post (as simulated below right).
I find that using files rather than the clipboard is still more incovnenient because I still have to use a file browser to navigate to the directory containing the image file. (Yes, there are things one can do to mitigate this, but they come with their own downsides.)
Yes, using forum software that allows uploading images directly, rather than having to use a third-party image hosting service, has some advantages. I'm glad to see that Ubisoft is moving towards that! I do hope that they bring over all the posts from the old forum if they move the older games to it, though. Having to search two different forums would be a bit of a pain. (Losing the history would be even worse.)