Is Android included?
No. Its using https://gs.statcounter.com/os-market-share/ as the source, where the 3 percent is from the desktop category.
Overall android has the biggest market share at 40% with windows as a runnerup at 28%.
What’s with the weird dip in windows usage and uptick in “unknown” usage?
Windows looks qute consistent to me. Android has a dip though, which could be caused by usage patterns, looking at the previous years the peak of phone usage is around summer. It could also be changes between browser versions and to some extend extensions for those browsers (firefox allows for extensions on mobile).
Looking at that sudden increase in OS X usage, I assume its related to the M1 chip? Although I still wouldn’t touch apple with a 6foot pole. People love to shit on Microsoft, at least they tend to treat their staff well. Everyone seems to have forgotten that Apple fitted nets at their Foxconn factory.
I can als troubleshoot any OS except stuff made by the fruit business as everything is hidden behind secret button combinations and lock outs.