You can still join a pool. I've tried it now with the Public-Pool and OCEAN. I'm not expecting to really earn anything. Just contributing to the decentralized hash rate.
Discussion
So a bit of a update for you. Right in the ocean stats it says IF a block is found my estimated earning is 1 sat. So I might go back to #Public-Pool or set up my own instance of public pool and treat it as if it's a lottery ticket. Since it has better chances than a lottery.