Landlines also often have a series of switches in between that add latency, and it is difficult to rewire those networks. One reasons Elon's space internet is likely to make money is that the electromagnetic route is the straight lines while undersea cables are not, giving it significant latency advantage for certain high-speed trading.

I don't remember the source, but that remote surgery thing was using a separate high speed network for emergency services only (edit: also vehicles and some industry), with 5G connection for the last mile.

Edit: correction, "5G consists of three connectivity types: enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC)", all of that is called 5G but those surgeries have almost nothing to do with the mobile broadband aspect that most people know from 4G.
So far in most places only eMBB 5G is being deployed, but they are starting by building the periphery layer of the 5G network, temporarily using the existing 4G network as its core, but this core will eventually be replaced with the more advanced 5G core infrastructure that can also support its mMTC and URLLC applications.
The hardware that underlies each connection type is not necessarily the same.