Sadly yes. mod_pagespeed is basically dead.
Speaking frankly as a web developer who depends on mod_pagespeed a lot, I have forked the repos and I've managed to carry the code forward enough to successfully build the master branch and get the .configure to run with Nginx (it doesn't yet build), but it's very, very slow progress working out what does what and seeing how it all hangs together. IF (and it's a big if!), I manage to successfully get a running version of ngx_pagespeed on Bazel I'll publish the code and binaries for all to use but it's a cumbersome beast to work on and sadly I haven't noticed anyone else attempting it at the moment. I would love it for someone or a company to carry this forward who is better skilled than I am but sadly despite having a lot of people using it, no one wanted to maintain the code.