I've kept the Flask one up to date for almost 10 years, all free updates.
I have so many course ideas but starting a new one is tough because I've lost all search traction to my site and courses in general. I don't want it to end but I also have to be real.
I've put a decade into writing blog posts, hundreds of free YouTube videos (without ads or sponsors), 100+ episode podcast related to programming and none of it has grown an audience in 5-10 years. I mean sure I have 21k subs on YouTube but most videos get like 200 views. I do it because I enjoy it but that doesn't mean it's wrong to also want to be able to sustain myself again doing it like I did between 2015 and 2021.