It is okay for privacy, especially if you dont have google app installed, but it is not security and privacy focused.

If you have google app installed I imagine it is probably as private as stock os on a pixel, but less secure. Graphene/calyx will definitely have better security and privacy than lineage with or without gapps.

But I understand there is other tradeoffs besides just security and privacy, like minimizng ewaste, cost, availability, etc.

It's good for general computing, and if it's off the internet it's good for anything. But if it's networked don't trust it with things you're not comfortable being at higher risk.

So watch YouTube fine, banking maybe not

The context here is a phone that's no longer receiving hardware security updates, not lineage OS itself. If you put lineage on a modern phone getting updates, then I'd be comfortable using it as a standard phone doing all the standard things including online banking

You don't have privacy if some criminal has access to your phone.

From Kuketz - "Overall, LineageOS leaves neither a privacy-friendly nor really secure impression"