The default choice should be the base model Raspberry Pi 4. The other options (compute module, Zero, higher RAM versions) are for specialized needs. Even if you’re using the Zero or Compute Module you probably want the normal Raspberry Pi 4 around for development.
Same. If you're shopping for a ras-pi, I think you're already in the market of people that are ok researching many models to find one that matches your use case best.
It's different from, say, apple having 10 different types of mac books each for slightly different use cases.
The default choice should be the base model Raspberry Pi 4. The other options (compute module, Zero, higher RAM versions) are for specialized needs. Even if you’re using the Zero or Compute Module you probably want the normal Raspberry Pi 4 around for development.