> I’m trying to understand how removing an entire sheet of gypsum

This is a fixed task. Required if you install the conduit or not. You have to cut the wall to make the port. If you have the port you can just use a slightly longer conduit, brace it where you can reach, and oh no you need an extra 2" of cable?

  > Raceways are unnecessary in stick built houses
 

Your mental model is too naïve. Have you done this before? Have you then replaced it or added additional lines?

The conduit makes all that easier, and provides the additional protection that I discussed. By having a conduit you're far less likely to get snagged on something while fishing the lines. You can stop hard corners that strip your cables while pulling on them. It's also a million times easier to see while you're chasing those cables. Sure, your house is a framing with wood but you still have insulation and who likes icy hands?

Really, think about it. What is the cost now compared to the future?

Is an additional 10 or let's even say a crazy 50% additional work now really that costly when you have to do the whole thing again in the future? And multiple times? It's a no brainier lol. Definition of chasing pennies with pounds. Just be nice to your future self. Be lazy long term, not lazy short term because lazy short term requires more work