How is it a scam? If it was that bad nearly all companies would just use in-house recruiters
Someone has to do the work of pestering software developers on LinkedIn. If the external recruiters didn't do it, companies would just do it themselves.
One thing is that in many cases recruiters cast a very wide net and can't distinguish competent from incompetent developers. This low signal-to-noise ratio means companies create increasingly more difficult interview processes to basically see if the people can actually code, in extremely artificial environments (LeetCode problems, etc).
That means you lose out on people who are actually good if you just talked to them for 30 minutes, but got screened out because they didn't remember CS algorithms off the top of their mind after 15 years in the industry delivering actual products.
I tend to believe you are right... But neither one of us can tell it for sure.
Notice that you have written a trademark on your comment? Only the people that work on that place get to know, or to decide if there will be a scam or not. They get full control of what's happening.
Someone has to do the work of pestering software developers on LinkedIn. If the external recruiters didn't do it, companies would just do it themselves.