Is there an equivalent for the JS ecosystem? If not, having Dependabot update dependencies automatically after a cooldown still seems like a better alernative, since you are likely to never update dependencies at all if it's not automatic.

RenovateBot supports a ton of languages, and ime works much better for the npm ecosystem than Dependabot. Especially true if you use an alternative package manager like yarn/pnpm.

Too bad dependabot cooldowns are brain-dead. If you set a cooldown for one week, and your dependency can't get their act together and makes a release daily, it'll start making PRs for the first (oldest) release in the series after a week even though there's nothing cool about the release cadence.