Almost all the failures of battery cables I have seen have been crimps. OEM crimps.
The autoparts store replacement cables are mostly horrid too, stamped steel ring terminals with a holee drilled through them.
I've not seen properly soldered battery cables fail, but I've also seen very few of them.
I have seen improperly soldered battery cables pull out of the lug/ring terminal on inspection when troubleshooting. They 'appeared' to be soldered properly, but the yank test revealed otherwise.
The melting of wire insulation and the possibility of a visually acceptable soldered but compromised imperfect or far from perfect connection, will have me continue to use the crimper and 2 layers of adhesive lined heatshrink on battery cables.
The unoxidized wire stranding will have been hit with Deoxit Shield before hydraulically crimping with the proper die size for the lug.
If it were someone elses money buying cables and terminations, I'd practice soldering battery cables until I was proficient at it. Then I'd have confidence in my own, but confidence in other's soldered work would still be suspect.
the whole vibration and solder breaking wires thing would likely mean very poor soldering method allowing excessive wicking, and improperly secured wires/cables combination.
Either way both crimps and soldering can be done visually acceptable and be far from a quality mechanical or electrical connector.
Smaller important terminations I do both, but insure solder is not getting onto the flexible portion.