I keep thinking that "employer" is the biggest confounding variable here. A quick survey of some of the big players, whom I would presume pay premium salaries, seem to favor spaces over tabs.

e.g.

https://google.github.io/styleguide/cppguide.html#Spaces_vs....

https://docs.microsoft.com/en-us/dotnet/csharp/programming-g...

I can't find an Apple style guide, but the first file on the most recent commit to Swift uses spaces as well.

https://github.com/apple/swift/blob/e0f75bf841631a50f9ab6502...