Easily VSCode, if we're talking about developer reach. I'm not big into Microsoft stuff, but almost every 'serious' .Net developer I personally know is using Rider, so I can only assume that Visual Studio is retreating to the same space occupied by Eclipse and Netbeans, i.e. still used, but mostly only in places where change is hard.
I'm an emacs user and even I keep a copy of VSCode installed just because I occasionally have to interact with SQL Server and it's really the best way to do that on non-windows systems now that they're winding down ADS.
I work at a mostly .NET firm and almost all the developers on that side of things are on Visual Studio. Rider has less penetration than PyCharm has among the Python devs.