PairDrop [0] gets the job done as a "good enough" cross-platform / cross-device AirDrop replacement if you're on the same network.
For practical, casual use with non-tech users (likely on cellular or not the same network), you do need an internet connection though (you can make a temporary "room" that you both join to then facilitate the transfers), and the caveat there is that method transfers slower than if you're on the same WiFi.
It's basically "we have McDonald's at home.." for file transfers lol, but I use it all the time!
gmail :)
Not kidding, Most of the time, when I want to send something from my device to my laptop, I share it with an email. In case of friends, directly in Viber, and Teams.
It depends on how big the file is. I've used everything from ftp (for videos), to Dropbox, or filetransfer.io (6gb limit), to send.now (maximum of 100gb), or even a USB stick (if they are local and you don't need the stick back right away).
Look into Sendme and AltSendme which is a GUI around the former, they use iroh which is an open source secure peer to peer relay service to send data so there are no limits whatsoever for sending and receiving files, because there's no central server.
For practical, casual use with non-tech users (likely on cellular or not the same network), you do need an internet connection though (you can make a temporary "room" that you both join to then facilitate the transfers), and the caveat there is that method transfers slower than if you're on the same WiFi.
It's basically "we have McDonald's at home.." for file transfers lol, but I use it all the time!
[0] https://pairdrop.net
(I'm not affiliated with any of these sites)