There are different reason about their zero liquidity, such as
1. Chaincase only available for iOS device and still on TestFlight/beta phase. As for sakewallet, i can't even find their website.
2. Both of them has very little publication. I just heard existence of sakewallet from your posts.
3. Wasabi Wallet only use their own CJ server. If the software force user to choose CJ server which show several alternative, i expect few user would choose different CJ server.
1. Chaincase app coordinator is available for all platforms where Wasabi Wallet can run, or do you mean iOS users, in general, aren't that interested in making CounJoin transactions? As for sakewallet's website, I only found this:
https://trustedrevie.ws/reviews/sakewallet.com, but the domain has been suspended, so my guess is that this project has failed.
2. Again, this only indicates that very few are really interested in finding alternatives to default coordinator.
3. I don't know what those users would have chosen had they been given such a choice, but you can't expect zkSNACKS to add alternative coordinators to the client because their income depends on not including anything alternative.