If this hadn't been the case, we'd be farther along now.
I don't see how, for example, Explorer being free held anyone back.
Do I need to spell this out any more for you?
Besides, many other browsers are available on Windows. ActiveX failed in the marketplace.
And no, at the time, many other browsers were not available on Windows, as they had a tiny market share, largely due to how incompatible they were with sites.