They absolutely did! It was getting companies to agree to skipping straight to the onsite after a 15-minute recruiter call.
This lets you skip the back-and-forth of screen scheduling and result chats. In turn, that saves weeks of time during a job search, and allows you to have all of your onsites within a short time period, and then and offers come in within a much narrower window of time. You can make apples-to-apples comparisons about which role you might take that way, so it's a much lower cost for a much greater payoff to spend a few hours interviewing with a company you weren't thinking of to see if it's a fit.
In my mind, this was the absolute killer feature. I am still at a Triplebyte job 7 years later that impressed me via their onsite, and I would not have thought to apply if they had not been on TripleByte's skip-to-the-onsite list.
A failed onsite is more expensive than if the candidate walked in the door, grabbed someone's laptop, threw it out the window, and left. That's a big deal. Even a 15-minute phone screen at typical Bay eng salaries is like a nice steak dinner (particularly if you include disruption to actually go do it).
The core problem that companies are willing to pay for is "top of funnel". The obviously skilled, experienced software engineer that every company wants. How do you make them interested in your company in the first place? Triplebyte did not really have a cost-effective solution for that, although that's what people wanted most when buying their service.