IIRC, there's work on a JS/TS capable macro API that can be used in the future. I will say, the effort MS has made to feature parity for Office's web interfaces is pretty impressive. I also say this as I've been planning to move my personal usage completely to self-host options (NextCloud, OnlyOffice, etc).
> Although you can't create, run, or edit VBA (Visual Basic for Applications) macros in Excel for the web, you can open and edit a workbook that contains macros. Any existing macros will remain in the workbook, and you can open the workbook in the Excel desktop app to view and edit the macros.
https://support.microsoft.com/en-us/office/work-with-vba-mac...