My computer network and software I use for work run under win98SE. It all works fine, I have no need and no wish to 'upgrade' - why fix it if it ain't broke?
On the other hand I do recognise that more complex operating systems may be needed for certain applications. In the meantime I'll continue using my outdated OS, with it's outdated Office '97, and it's outdated Sales / Purchase / Stock Control / Accounts programme. It does what I need.