Electrical solderless or soldered connectors

Last year I completely redid an underhood wiring harness for my 85 D150. Repaired a few "aged spots" that insulation was deteriorating, replaced a few wires, and wired in an underhood fuse box from a different application that incorporated maxi fuses so I could do away with any and all fusible links. I hate those things. (Nother story); I crimped every connection with a bare uninsulated butt connector, soldered every connection I made and used the good grade of heat shrink (adhesive lined, not the stuff that is usually bought at Lowe's or ace hardware) So far so good. But I've wired up more trailers from scratch over the years than I can remember and in an application like that I've noticed that if I am gonna later have issues, it's a broken wire and/or corrosion right next to a soldered joint. I don't get that. I don't use acid core, never have.