Microsoft stopped supporting it. VB 6 was the last "true" Visual Basic. The .Net Visual Basic was not backwards compatible with the very large code base projects everyone had created over the years and ones on forums and websites like planet-source-code (before GitHub existed) and the many, many beginner-friendly books.
They had a conversion wizard to migrate VB 6 projects to VB.Net but it was very half hearted and never worked on anything except the very trivial code bases. Anything that used OCX and you were out of luck, except OCXs were very very common in classic VB development.
People kept writing VB6 as long as it was practical (Windows 7) and then either moved on to greener pastures or left coding altogether as it was becoming impossible to use modern libraries anymore and the overall learning paradigm have shifted from books/forums into video tutorials and "modern" languages.
They had a conversion wizard to migrate VB 6 projects to VB.Net but it was very half hearted and never worked on anything except the very trivial code bases. Anything that used OCX and you were out of luck, except OCXs were very very common in classic VB development.
People kept writing VB6 as long as it was practical (Windows 7) and then either moved on to greener pastures or left coding altogether as it was becoming impossible to use modern libraries anymore and the overall learning paradigm have shifted from books/forums into video tutorials and "modern" languages.