Although this piece is ostensibly about why we should be using web workers more, there’s a much, much bigger point about the growing power gap between the devices we developers use and the typical device used by the rest of the planet.
While we are getting faster flagship phones every cycle, the vast majority of people can’t afford these. The more affordable phones are stuck in the past and have highly fluctuating performance metrics. These low-end phones will mostly likely be used by the massive number of people coming online in the next couple of years. The gap between the fastest and the slowest phone is getting wider, and the median is going down.