I don't think time alone solves it. It's a market issue. Basically, there are more freelancers (even good ones) than demand for them. This is the case with every similar platform that I've seen or registered to in the past. For example, I've tried gun.io about 4 years ago. Maybe even found them here. Big words ("we're professional, only work with the best, tell us your minimum rate and will get you the best rate possible", etc.), simple website, simple process (write proposals and they'll do the agreement part), big waste of time. I've spent out like 30 custom proposals (that's around 15-20 hours of time wasted) and never heard back from any client, except for maybe one, but haven't even got to talk to that one either. And of course (signing up twice) I've got two confirmation emails from them in response to their usual entry test proposal saying "welcome, this is the quality we're looking for", etc.
Now as they've transitioned into a slack community a few months ago, I know that they are nice and well-meaning guys, but they just weren't able to stand up for their (you can say partly implicit) promises. And you can do quite a bit of harm and be a prick by simply not being attentive enough. For example in their case, they have like 10k(!) developers signed up. And to sign up, every one of them (us) had to fill a profile (there go 30-60 minutes, times 10k!) and do a sample proposal (which wasn't clear was just an entry test - maybe it wasn't). Now in the new slack community you can see all the gigs being posted and it's like 1/month or so. For the thousands signed up. Even if they keep working with the same freelancers as much as possible.
This is not the only example, I've seen the same with a few other companies/services, but went into the details with this one, because with them I could see behind the curtains. (With the usual website they just never get back to you, or your proposals just never get answered.) Another similar one is codementor.io, which started out as a programmer-to-programmer mentoring platform (which I do use as such) and who figured out a while ago, that they have quite a few knowledgeable developers, so they could just feed us with projects. Same thing happens: very low deal flow, quite often no feedback after submitting a proposal. (Which is just shitty customer service, of course.) Even though in their case, I do quite a bit of emailing with them (e.g. reporting bugs, suggesting usability fixes, and also sometimes they explicitly reached out for me to help with specific projects/clients in the beginning).
So this shows to me that while there is a huge unserved demand for developers, there isn't such a big demand for freelancers. Which, if I'm honest to myself, kind of makes sense. Most companies will want to keep accumulated knowledge in-house.
But despite the market situation, I'm still a bit angry with all these mediator portals. They should rob the time of everyone and sign them up in bulk. It would be a lot more responsible to say that we have enough developers for now, come back later or leave your email address and maybe a few tags and we'll ping you when there is a substantial chance that we can give actually you some work.