Many years ago, when computers were
room-sized, and consumed megawatts of power,
I was on the wiring installation team.

We used 4/0 cable, and all connections
were made with copper squeeze clamps.
( then wrapped with fish-tape and cloth as I remember )

When we asked about soldering the connections,
the power engineer gurus claimed that
lab tests proved best connections were
copper-to-copper compression.

Of course we're talking controlled environment.
No humidity, water, salt, etc.
rj