there is basically no tooling or software support because it is seem as a Blockstream thing, not a community thing
it doesn't actually provide privacy out-of-the-box, you need someone to host a coinjoin pool inside and there are none -- whereas the zSide sidechain would automatically be that perfect ongoing coinjoin with no overhead, cheap fees and great UX
because you have to do KYC on an exchange to withdraw
Maybe no one uses Liquid because