Thanks a lot for the post, Joseph!
Your ideas here in this post and earlier at Appsmith freelancing session (a couple of years ago?) are insightful.
I was always allergic to classical freelancing platforms, but you had some strong points in the past that a marketplace can serve as a trusted third-party and also help deal with international clients.
Since the platform attractiveness decrease, something like Deel could be a good substitute: not a marketplace, but a good service for making contracts and handling payments.
As of the incoming leads vs outgoing messages: I thought chasing clients on marketplaces is a road to nowhere. Or better to think about it of a hamster wheel: same routine every day.
That's why incoming leads are number one priority for solo freelancers / small teams of devs. Building some useful stuff and sharing it for free looks a much better time spent. Because at the end of the day, you have an asset that you can give away or put into a CV. "Replied to 100 jobs" is not something you can add into the resume :)