I personally browse with JS on (with a lot of filters), but I know a lot of people who have it off and whitelist sites that are broken without it. Sometimes on a per-script basis.

Main reasons are for extra privacy (scripts aren't there making arbitrary requests), better responsiveness, and better battery life etc. Of course there is a cost.

Whitelisting and turning on scripts a feature browsers come with by default?

I usually browse with JS only turned on for top level domains that I visit, then manually turn on the media domains that feed pictures or video, if I want to consume that media. If I frequent the site, I white list it.

I enjoy the faster load times for most sites, less battery drain, no auto-playing videos, etc. It took awhile to get used to, but now its just the way to surf (for me) nowadays.

Nice. Sounds reasonable.