[modeless]

I don't have a choice of ISPs. It's not a competitive market and they have no incentive to respect my privacy in the slightest.

In contrast I can choose any VPN provider in the world. It's a competitive market and they have strong incentives to respect privacy because it's one of their main selling points. Any VPN that is discovered to not be respecting privacy will lose a lot of business in short order.

Sure you can say that they can violate privacy in secret, but that's a big risk for them. It's no risk at all for an ISP because their customers have no choice. It's no guarantee, but it's definitely a better situation to use a company that actually has incentives aligned with yours.