You are correct, and I use it myself, right up until you aren't on the same local network...

I actually haven't tested whether it works if you make a mobile hotspot... But being out in a bar that doesn't offer WiFi, would then require you to first set up a mobile hotspot, get the other person to connect, then download localsend before you can actually transfer the file. And even if the bar offered WiFi, you would kinda hope that the bar has enabled client isolation on the network to avoid spreading malware... But that would in turn defeat Localsend.

With Airdrop you don't need any of that, given that both people have iDevices

LocalSend is so good 👌