As a vscodium user i can tell you that is not true. I had to debug a c# unit test this week and for the life of me could not get it to work on vscodium. The c# extension cant run in vscodium and the same is true for the debugger. There are alternatives but it just would not attach the debugger when i hit debug tests.

Installed vscode with the c# extension and it just worked, sadly.

Still using vscodium though haha