I share the feeling that I wish there were more resources out there. I've collected a motley set at https://justinblank.com/notebooks/jvmarchitecture.html, but I haven't found anything systematic.
Some other great resources I used:
* http://psy-lob-saw.blogspot.com/ - Not updated since 2018, but still great stuff in there
* https://richardstartin.github.io/ - A few posts per year. Richard does a lot of interesting things.