Another ongoing from over 10 years ago, is Awful Hospital. it also started in 2014.

This is a bit like MSPA (or early ksbd) in that it had a lot of reader interaction.

This was a bit of a mixed media one, kinda like MSPA or homestuck. You had videos, flash animations, comics, and text. It's still on going.
https://bogleech.com/awfulhospital/intro

It updates kinda slowly.