Are prebuilt roadside emergency kits actually worth buying?

Specialist communities like r/preppers and r/AskDad consistently argue that DIY kits are higher quality per dollar, and they're not wrong. But mainstream reviewers at tomsguide.com, popularmechanics.com, and nytimes.com note that a decent prebuilt kit gets a non-enthusiast covered immediately for jumper cables, a reflective triangle, basic first aid, and a tow strap, which is better than the kit most drivers will never assemble themselves.