> Scalability is about minimizing bottlenecks and linear scaling so one can just copy and execute by adding more nodes/resources and expect correctness and increased throughput.
Yes, technically, but note that this entire thing can be anything from crucial to completely worthless depending on the domain.
You need insane scalability for a social network or a streaming service, you don’t need any real scalability for (completely made up) managing a fleet of airplanes or the internal logistics of a zoo.
Writing scalable and efficient programs are extremely hard. This matters for serious projects but for small projects, honestly who cares.
The almost all problems are "small", by your standards. Giant market.