Since solder is such a poor conductor, why use it?


Why would we not weld all joints. Welded silver or copper wire would not have the loss of conductivity of going through solder.
tbg
Even better yet...forget welding which is so old school to start with, form the entire circuit end to end and with no wires and with no connections to solder. I bet someone somewhere is doing this already to some extent but they have way more money to spend than anyone here. Bigger better integrated circuits per se. Oh wait, point to point wiring sounds better than that already. Oh well, back to the drawing board....
Timrhu, yes solder is awful now. It cracks.

Tbg

Sure solder joints crack if not done properly. But they also will out live us if done correctly.
if you are not happy with solder then you could always try conductive epoxy! Drying time might be the only issue :)

For me, silver solder is fine and it seals against oxidization, just ensure that the pieces being soldered have a good connection and try not to use too much solder. Also, using a good flux paste ensures good eutectic flow :)
Electron tubes are not soldered into place. All those ribbon connectors are not soldered. Why not use tiny little mechanical connectors instead of solder? Has anyone actually measured the losses due to all the solder connections? One wonders how much it could be and compared to what.