system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do many heavy duty vehicles use manual transmission?

Why do many vehicles used for heavy work, like trucks, bulldozers etc. use manual transmission instead of auto?
gpt
Manual transmission is a lot more robust and easier to repair if something goes wrong while also being a lot cheaper, and in the right hands will tend to outperform an automatic transmission in most metrics too.

The only benefit to automatic transmission is that it's a little easier to use, which just isn't that meaningful when you are talking about big expensive pieces of equipment that should only be operated by a professional in the first place.