Committing to a new process or software is an investment of time and trust. When we choose something to use in our group, we want to know it's going to be there in a year or two, and still doing the thing we bought it for.
Software you can purchase and install on your own servers / desktops does that. In fact, we'll choose one software package over another if it doesn't force us to submit to updates until we want them, or rely on someone else's servers to stay functional.
Browser-based tools from someone else can make it into our workflow, but only after they've been around long enough and achieved mainstream adoption, so we can be relatively sure they're unlikely to "pivot" or disappear. Google Docs and Slack are good examples of this.
When you're new and unproven, there are already a lot of hurdles to leap in order to get users, especially business users.
Making your software user-installable eliminates a huge hurdle, I would recommend it.