They do for sure but it's just me thinking they don't have enough room. They are very active fish.
My original endler was in my 20 long but was very territorial with my cardinal tetras and 2 of my guppies were agressice with him so he ended up being moved to my 10 gallon. So I guess it comes down to me feeling bad for putting him in a smaller space.
Edit I would never recommend endlers or guppies in a 5 gallon