I am living through this right now and have asked this questions on several forums because when you're really in the midst of this hustle you start to question your priorities and constantly get this feeling about if there is a better way. This is a counter-intuitive advice on building a product and a company but the other option would be to get lucky.
Couple of more examples about doing things which don't scale:
Instacart manually built their product catalog for the first few million products.[0]
Pandora analyzing 10,000 songs manually for recommendation. [1]
One thing that isn't captured nowadays is that a lot of what "couldn't scale" before - i.e manual work, the type of which you described - is now much more scalable due to how much easier it is to automate tasks at scale.
It's suddenly feasible to build businesses that require at-scale manual operations, because you can do so in a predictable, revenue-positive way.
"Do Things That Don't Scale" is not a choice which founders make even if they have all the resources and technical chops. If you don't know or unsure what to focus on then how do you decide to optimize and improve it?
Take Instacart for example, what would you have done differently to build the catalog given you had same information what Apoorva had at that time? Same for Pandora & Airbnb...
Couple of more examples about doing things which don't scale:
Instacart manually built their product catalog for the first few million products.[0]
Pandora analyzing 10,000 songs manually for recommendation. [1]
[0] https://youtu.be/uV4lzz1Z0C8
[1] https://youtu.be/bTtq-M9iDHI