Cydia technically still exists, Saurik is not inactive to my knowledge. But installing it these days is a PITA... The glory days of jailbreaking (jailbreakMe, limera1n, ...) are sadly far behind us. :(
That said, it wouldn't be impossible to set up an APT repo and host a prebuild zap-enabled Damus there. But the amount of potential users is probably in the single digits. :/