Started getting into martial arts a few years ago (late in life). Stretch and train almost every day, I’m nowhere near close to being able to do a split. At some point, it definitely takes more than just practice.
I’m not saying it isn’t possible, I’ve seen guys older than me do it, but age, sex and past experience and training definitely play large factors. My wife doesn’t stretch at all, hasn’t exercised on a regular basis since she was in highschool (she was in cheer) and she could get a LOT closer to a full split than I can.
There’s a drinking game called 7’s. Basically everyone has to count by 7 (first person: 7, second person: 14, third person: 21, etc) and you have to take a shot every time you get one wrong.