Would anyone be interested in a desktop application with similar functionality, accessing [multiple] hosts via SSH?
Depends. Open source or proprietary? Actually desktop or just electron? Are you going to maintain it? What use cases would it be intended for? Would the client software be available for macOS? Which GUI framework(s) would you be using?
use cases: server management and monitoring, log viewer, ssh terminals, parallel execution of commands, vnc, sftp, secure storage of credentials and keys.