Definitely shop around, but sometimes the dealership does have an actual competitive offer. Especially if you threaten to use external financing (and have the pre approval in hand), they might knock down their interest rate to save the deal, as the loan is where the money actually is.
Bill Nye kind of is a dick though.
Some people are really warm in acute person-to-person interactions, but lack the chronic empathy to spread long-term kindness. See “southern hospitality” clashing with who those areas vote for.
Others have a well-oriented moral compass but are just really abrasive in person. That’s Bill Nye. I’ve met him and he’s not like, super mean but he’s got a bit of a holier-than-thou (or rather, smarter-than-you) complex.