To my knowledge jars are precompiled, not interpreted. Also, jars can run on any platform that runs Java which can be handy for easy distribution.

Had this exact same issue when I clean installed Windows 10 (because my new laptop came with 11), that was a fun couple hours of my life

That one's pretty simple...

if ((!(schoolHours == false) == false) ? false : (schoolHours == 1))

No hosting platform is truly rock-solid, as people have pointed out in this thread. Personally, I keep some projects on GitHub but always keep a local copy as well, and (hopefully) that's enough for me.