I notice sometimes web browsers like Firefox and Chrome seems slightly faster on a Linux based operating system like Lubuntu installed on a computer compared to running Firefox and Chrome on Windows 10 on the same computer which sometimes feel slightly slower because of slowdown problems caused by Windows 10, Windows Update, or a third-party Windows software like an Antivirus software.
I use Microsoft Edge Beta which is based on Chromium web browser, and it run faster than Internet Explorer and the regular version of Edge which is based on IE.
But, Edge Beta still seem slightly slower than Chromium in Lubuntu Linux on the same PC.
I think for cheap $200 laptops like the HP stream with 2GB RAM and a cheap Intel Celeron, websites with a lot of ads, flash games, and HD videos would run slower in Windows 10 compared to using a Linux based operating system like Lubuntu Linux.
A few years ago, I used Puppy Linux on my computer, and its web browsing speed was very fast. I think Puppy Linux load the operating system and programs to the computer's RAM/memory which is faster than SSD storage drives. Plus, Puppy Linux is a very lightweight operating system, so most programs run very fast in Puppy Linux.