Ok, after more than one hour trying, I'm hereby declaring that the HTML5 Vibration API on mobile phones (at least on my Xiaomi using Chrome) is a scam.
Yeah, I'm like those cool people who fiddle with interesting stuff and write a post series during a whole evening, except that I always take the wrong turn and get stuck in the mud. My posts aim to be a celebration of success and end up becoming a rant in the end.
@cinnamon I'm trying to remember what my experience with that api was... I think it did work for me back when i was making this but it surely doesn't work right now
@kitten which version do you both have? the error @cinnamon has posted sounds like a bug, i wonder if it happens with other APIs that require sticky user activation
@kitten@cinnamon also, I would've sworn this thing was working in Firefox before... looked at why it's broken now and, surprise! they removed the vibration API so the code crashes now