>> Chrome's PIP is a stupid workaround for Windows and Mac because they do not have robust window management.
What are you talking about? It's very convenient when I watch video while I do some work or entertaining thing on other web page or app. It's fine if you don't want to use it but many people do.
Yes, it's fine, but it shouldn't be necessary. If Windows and Mac OS just had native support for always-on-top windows, you wouldn't need it.