Oracle is not dead but I would also use Oracle Solaris mainly when a support guarantee until 2034 is important or when best of all (SMB) performance is wanted. While the multithreadad kernelbased SMB server on the free Solaris forks ex OmniOS is fast, it never reached Solaris with native ZFS.back when Oracle closed off open source people started realizing its ALL ABOUT THE DATA...
ZFS was on a wining path, and with open source helping move it in both features and testing it was well on its way to becoming a possible new standard.
Now that openZFS and oracle ZFS have hard forked and are no longer compatible, in my opinion, openZFS will win due to cross platform compatibility and momentum
Oracle is dead
Without a support contract, I would not consider Solaris. There is a reason why OmniOS offers bug and security fixes every 2-4 weeks.