Wasn't the hugest reason that they stopped allowing people to write their own code in myspace and made it into something nobody uses anymore was because you could do code injection attacks on it? [1] I mean doesn't anyone else remember that kid who got convicted of a felony for getting everyone's myspace pages to say 'but most of all, samy is my hero'? [2]
[1] https://css.csail.mit.edu/6.858/2019/readings/advisory4.5.06...
[2] https://en.wikipedia.org/wiki/Samy_(computer_worm)