I prefer https://localsend.org/ nowadays. Nice cross-platform GUI, "just works". Requires being on the same lan, but discovery of other devices is automatic and there are no alphanumeric codes that have to be shared. It's a good QoL improvement to have "airdrop" between Android and Linux
I've had better luck with https://drop.lol/ - it allows local discovery but can also share a link (drop.lol/XXXXX) to invite a device to the "network". There have been a number of times/networks local peer discovery doesn't work for me, but maybe that's because I haven't installed the localsend app.