This is the reason I've never used discord outside voice chatting with friends a few times per month.
A basic photo from my phone is over the file size limit. It's essentially unusable, and I'm not going to get me and my friends and family to all pay a subscription for a feature literally every other chat app provides for free. Sorry.
When did they start this? Because I last tried a few months ago to send a photo and it was telling me it was too large, and to buy nitro. It was ~8.6MB