We've worked with enough engineers to be confident they're finding value and advantages to using Triplebyte. The feedback has included finding interesting companies (especially earlier stage ones) they'd not known about, skipping technical phone screens (even if you know you'll pass, they still suck), getting feedback on the Triplebyte technical interview, having interview scheduling handled by us, getting a high offer rate and help thinking through offers.

Assuming you can get companies to engage with you (i.e. you already have the right resume credentials) you could invest the time in achieving these same goals yourself as you're saying. For people who don't want to make that time investment, we can save time in a way that other recruiters can't by filtering companies using data about your technical skills and skipping those phone screens. The companies we work with don't trust other recruiters to do this screening correctly.

Our interview also doesn't require taking a day off work, it takes 2.5 hours and is done remotely via Google Hangouts.