My opinion is repl.it iterates fast, the CEO founder is very shipping and community oriented, and he's a good follow on Twitter: https://twitter.com/amasad
They were/are also incubated by YCombinator. They’re a darling here, for all the reasons you mentioned, but I also get the impression that they build in a “see what sticks” manner. I’ve found some of their recent announcements neat but not immediately valuable long-term or for non-casual users.