About what niche we talk about?
I believe the quality of backlinks really depends on the niche. But in general, most marketplace links tend to be overused and spammy — the same domains being sold to everyone. These links often don't provide much long-term value, especially in competitive niches.
If you're looking for unique links that actually move the needle, you're better off working with a manual outreach agency or a freelancer who specializes in custom link building. It can take time (sometimes up to 3 months) to find a good searcher/outreacher, but the results are usually worth the wait.