Microsoft effectively killed VB because they decided everyone should be using .NET. While they created VB .NET in an attempt to make the transition palatable to VB programmers, this was a second-class citizen to the CLR, and more importantly too different from VB, more akin to an inferior C# with VB-like syntax than actual VB. It was widely decried by VB developers [0], and nick-named "Visual Fred" due to really being a different language than VB. Microsoft ignored that, and also didn't bring a VB-like experience to .NET. It didn't help that mainstream software development started drifting to the web, and later also to mobile apps.

[0] https://classicvb.net/vfred/breaks.asp