Haha that's so funny! I do the exact same whenever I have to make anything platformer related - I get my partner to play it to see if it isn't just hard for me :)
Pff im glad im not the only one then! My boyfriend steamrolled through every level and I was just watching in awe because testing the level myself took agessss because im bad 🤣 I went through and made it harder after that and he would slip up here and there so I felt it had a better balance for the more experienced peeps! 🙌