I've used Triplebyte and Hired in the past as a candidate. Triplebyte is good only for web development positions (front or back), and Hired seems completely useless. Every time I get emails begging me to submit my resume and then immediately get rejected. Makes no sense at all.
From what other people comment here and my own opinion, the filtering that most job boards use are complete garbage. Sometimes I want to search for a keyword, but I have never seen a single search where I can exclude a keyword. Or some implied tags just aren't used to help expand or narrow search results. And also PDF resumes just aren't able to be parsed correctly, even in very simple formats. But I would never be able to tell if it was parsed correctly as an applicant for some ATS systems because there's no feedback. As far as I'm aware, digital resumes should be in more use, but every ATS requires a new account and inputting the same information. Even when the company board listing is provided by the same company as another board listing! Workday is one example of that and it's infuriating!
And then there's the whole problem of HR people putting out the job listings. The horrible inaccuracy of some of them makes it really confusing as to what a company is actually looking for and if I would be a good fit.
Basically, I can't find what I want, I don't know what's happening, and I don't know what you want. And the best way to solve all of those is to 1) make better search tools, 2) give me more feedback and tell me when things go wrong instead of rejecting me outright for a software error, and 3) have the person in charge of a position write the job listing or talk to the candidate.