Basically it is Flash all over again, just now it is built-in in the browser.
I think the world MUST start to make/tell the difference between (web)apps and web pages. Slack does not need to be written in js/html. Skype does not need to be written in js/html. They do those in electron just to avoid having to maintain X different code bases.
My reaction to using the canvas instead of the DOM is very, very, very negative by the way. Webpages with fake text that is actually pixels rendered to a canvas are currently mostly restricted to dystopian notions of either the end result of the ad-blocker arms race or else extreme anti-copying measures.