Depends on the model, but in general, no.
...but it's fine for simple 1 liner commands like "how do I revert my commit?" or "rename these files to camelcase".
> How often does it fail?
Immediately and constantly if you ask anything hard.
An 8b model is not chat-gpt. The 3B model in the OP post is not chat-gpt.
The capability compared to sonnet/4o is like a potato and a car.
Search for 'LLM Leaderboard' and you can see for yourself. The 8b models do not even rank. They're generally not capable enough to use as a self hosted assistant.