>When I generate a build package in Altium, it has complete lists of every part in the design, its MPN, at least one supplier to purchase it, and the SPN for that MPN. (Sometimes internal parts don't have suppliers assigned, but then they're tracked elsewhere in the project or company organization.) There are also assigned alternates in many cases, though they are typically inadequate. Larger projects should use entirely internal part numbering, but that's a real headwind for smaller stuff. All of this comes from a single master part database, plus a project part database, and never gets touched by hand after a library entry's birth.
Only if you've put in the effort to make that database in the first place, which Altium makes pretty annoyingly difficult. I really don't like Altium's mess of options for parts libraries, the defaults for which all suck and a sensible setup requiring a lot of fiddling. I haven't dived too deep into KiCad's setup here recently, but it'd have to try hard to be worse than Altium. The difference is cultural, not tooling.
We use the Celestial Altium Library [1], it's really good for passive components, which make up ~80% of our schematics by count. For other parts we first try to get them through Altium Manufacturer Part Search, we vet the symbol and footprints before importing them into our internal library. Other model sources in order of preference is SnapMagic, UltraLibrarian, Samacsys. Be aware as the quality is often half-baked. Between components that meet my requirements, I will always pick the one with CAD models easily available.
With those prerequisites I only have to make 2-3 footprints from scratch per project as needed, and less so as our library grows.
[1] https://altiumlibrary.com/