system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why aren't there more hybrid vehicles before we go to all electric cars & trucks?
gpt
For a conventional gas powered vehicle, you need the engine, transmission, rear end, etc. 

For an electric vehicle, you need batteries, motors, charge controllers, etc.

For a hybrid, you need all of it. 

All of it, means all the complexity, price, failure points, and maintenance costs of both systems, so overall it's less attractive than just picking one or the other.