Take a look at these:
https://www.amazon.com/Qibaok-Connectors-Insulated-Electrica...
Crimp a wire in it. Look at it from the connector side. You'll see the bare conductor inside the connector. That's where the moisture gets in. Heat shrink tubing won't shrink enough to cover that. Wicking solder into it will seal it against moisture and corrosion.
Never had trouble with the completed soldered/crimped connections for decades. I use them in my car. With crimp-only, it's only a matter of time till I get erratic connects. It's particularly irritating with the stereo, as the speakers go in and out or suffer the crackling with a loose connection.
Solder will fill any voids in your contact, causing the bond to break as your entire assembly heats and cools.
Solder will also wick up the strands, making the resultant wire brittle.
Moisture ingress can be solved with the correct wrapping. After all, the extruded PVC insulation on the wire in the first place shrunk to fit it, right?
https://www.amazon.com/JRready-Connector-Waterproof-Electric...
The cheaper knock offs can work well, too.
I have electronic equipment in nearly continuous use for 40 years. Daily heat/cool cycling. No solder breaks in it.
It seems that this debate is an old one:
https://www.linkedin.com/advice/0/what-pros-cons-soldering-v...
https://blog.peigenesis.com/soldering-vs-crimping-advantages...
https://www.sig4cai.com/soldering-or-crimping-which-is-bette...
P.S. I'm pretty good with soldering, since I've done it professionally, so the disadvantages of a poorly soldered joint don't apply.
My crimped and soldered ones work fine, though, and cost basically nothing.