It absolutely is slower. To an extreme degree even. It takes 10 to 20 seconds to load and is incredibly sluggish to use on some low-end machines I use regularly.
I disagree that we should be optimizing for low end machines and holding back on product improvements for the 80% mass market. Technology improves, it’s one of its best traits. We don’t need to be stuck in the past.
I think those machines are super fun and a snappy Linux experience is very satisfying. I use a lightweight WM myself on Linux and prefer it over the heavy ones. But this segment is 0.1% of technology users and we shouldn’t constrain applications to the limited hardware that this population chooses to use.