I'm looking to develop a VSTO Add-In for Excel as deploying my Add-In made via Office-JS framework just simply failed via M365 Admin Center.
But, I don't want to use Visual Studio, can I develop a VSTO Add-In using only Visual Studio Code? I can certainly get my hands on a template generated by VS and then look at setting that up in VSCode.
Visual Studio Code doesn't provide any tools or extensions for VSTO add-ins. VSCode is used for .net core projects while VSTO add-ins are based on .net framework only. Note, you can download the Community edition where you can build VSTO add-ins.
However, Visual Studio is not a requirement for building any kind of software. The question is how convenient the process will be without it :)