If you have 8GB you can play around with heavily quantized 7B models, or up to moderately quantized 13GB models w/ 16GB.

Something like a Mistral-7B Dolphin finetune actually is surprisingly useful, like GPT-3.5 in some respects. I imagine it would render ~10 tok/sec on an M2 for at least short bursts until throttling sets in.

As I mentioned in another post, try this out with LM Studio. Super simple GUI that even a non-tech person could probably figure out for finding/downloading/loading models w/ a ChatGPT like interface for chatting.

https://lmstudio.ai/

Without knowing what you consider to be of worth, that's difficult to answer.

The good news is that the article describes in detail how to determine for yourself if it's worth it. The author uses an M2 as well, so you can at least know it'll likely work.

It depends on what you want them to do and what you want to get out of them. A lot of people use less machine than a M2 Air for different things.

I have Ollama running llama 7B on an 32GB Mac M1 Pro and its fast enough to be useful.