The thing is, you’re not putting a dissertation on one of these signs. You’re already supposed to yield on a solid green if you’re turning left without a green arrow, that’s already the law. This sign is a reminder for the stupid people about something they’re already supposed to do, not allow someone who’s never driven in their life to learn the laws as they go.
A driver that doesn’t know the standard road signs and road laws is more dangerous. Stopping in the middle of the road to figure out what a common sign means isn’t being careful, it’s being a bad driver and making the road more dangerous for everyone else.