You can. You just need to know how. You have to paste a link to a picture, you can’t paste the picture itself.
There’s a discussion here on how to make it work.
I don’t remember being able to post pictures on the old board within posts, just links to them.
It’s sort of like trying to drive when you’re new to cars, and after driving an hour griping about how you miss your bike, even though your bike couldn’t have gotten you to where you drove.