TIL You can ask Siri on the Mac to make your iPhone ring
And it rings almost instantly !
It uses Find My iPhone in the backend for that, but it is much more convenient than opening Find My IPhone in iCloud.com which is horribly slow to load.
I use Siri in French and I can ask my phone to ring but based on the comments it seems the phrasing is a little bit different in English. You have to say something like « Find my iPhone » or « Ping my iPhone ».