Also agree, this isn't intended to be a replacement for direct access, nor for streaming purposes.
This gives you and RDP session with no software install needed. The use case of guacamole is accessing a system from anywhere without needing your ssh keys, RDP, or VNC software. If you're happy doing any of those directly, adding a middle man doesn't add any value.
That said, if you're managing others accessing the system, you can bastion of the target machines and only expose this access. This lets you put the target machines behind NAT, and only manage one entry point.