Oh so this is very very different and it would be unfair to say one is better than the other. They're transmitting raw drawing commands a la RDP or X Forwarding

Oh so this is very very different and it would be unfair to say one is better than the other. They're transmitting raw drawing commands a la RDP or X Forwarding which provides pixel perfect rendering and website compatibility by running the JS in a remote browser instance. I wonder how that impacts accessibility, screen readers and ARIA. If they're rendering a Canvas element as a framebuffer, I have to imagine they've lost support.