> The problem with Office.js is that it’s just simply too hard to get started with all the npm bloat for the average Excel user (even more professional devs struggle)
IMO deployment is an even harder problem. The Office team makes it incredibly difficult to deploy web add-ins (presumably for business reasons) and accordingly most companies I'm familiar with are still using the ancient, barely-supported COM+VSTO add-in models.
The part that makes it a non-starter is that it has to be in some kind of a store (whether it's on prem via SharePoint) or the Internet. What is needed is that you can install something on the user's computer (xcopy install, msi, w/e), but without requiring any other Microsoft end-point. And then, the bits installed either run completely on-node (similar to COM/VSTO) or it would require that access to remote web-server be required. If a remote web-server is required (which is a bit of a limitation), it should be something that can be pointed to without Microsoft's involvement. Just like I can create a web-site, give you a URL to it, and you can go it using your WebBrowser. No app-stores.
That doesn't mean app-store shouldn't be an option. I would love to also publish my add-in in the Microsoft AppStore, but it should be my choice, not a hard-requirement.
That's why people are still using VSTO, not because we have a problem with JavaScript vs. C# or COM.
The app store / Office admin stuff. When I was dealing with this stuff 2 years ago, it was insanely difficult to deploy a web add-in internally (something involving the "Microsoft 365 admin center"), let alone deploy it to customers (gotta get approval to deploy it in the special Office app store, and hope+pray that your customers' IT departments don't block that).
Compare to VSTO, where IIRC installation just involves editing a registry value to let Office know where your add-in can be found on disk.
You just reminded me I tried to make an office addin a few years back and distribute it on the office store. Terrible experience trying to get Microsoft’s admin/business center (whatever it is/was called) to verify I was actually a real human/owner of the domain as a sole proprietor. Terrible.
IMO deployment is an even harder problem. The Office team makes it incredibly difficult to deploy web add-ins (presumably for business reasons) and accordingly most companies I'm familiar with are still using the ancient, barely-supported COM+VSTO add-in models.