There should be a reminder about the jam ending on e-mail if I remember correctly. Sometimes people make games or assets in jams and life hits them or they just are not happy what they have made and thanks to that they have not submitted. I do know that developers are simple if there is an insentive to get something they are more likely to join and submit, maybe even if its just 5 dollars or recoqnition on social media or anything alike that, a good name for the jam.
You can also if I'm not wrong directly press on the user and message them through email (At least you could a year ago not sure now).
I have as well joined multiple jams made and focused on games, but just didnt like it so I ended up not submitting because I just felt bad submitting it, I think its fine. 3 Developers are already a huge sum I have seen a lot with nothing.
It would help participation greatly if there were better templates to learn from than basically nothing in unreal and unity outside of the "BUY MY BOOK/COURSE" scammers shilling their snake oil all over the internet. I still cant get animation blueprints to work properly outside of guess and check and forget trying to retarget animations with models you made yourself. Everyone will just gaslight you that the documented feature doesn't exist in UE4/5.
Where you are expected to redefine the entire concept of reality from scratch and all of the elitist asshole programmers who have experience would rather sit back and laugh at your inexperience instead of providing anything helpful to collaborative efforts and then get found out as the hacks they are when 99% of the assets they used were just flipped right off the asset store and their "games" are just buggy messes they never intend to fix even in the context of a learning experience.
