Transferring files between devices

It’s surprisingly difficult to transfer a file between a phone and a computer or between two computers.

If you have a Mac and a mobile Apple device of a similar vintage, it’s fairly simple to do if you can remember the name of their proprietary software Airdrop.

But any other combinations of devices you’re out of luck if you want to easily transfer files without going through a cloud provider.

Why aren’t there any open standards for this? Why isn’t simpler after all these years?