There are several freelancers on Upwork earning tens of thousands of dollars yearly.
It doesn't change the fact that everywhere I turn, I see an Upwork freelancer telling me how they've been there for years; hundreds of proposals sent, no reply.
The first group is the exception

It would be sad if the ones making it big there—getting their proposals replied, 5 star ratings from numerous clients—look down on the others as lazy, unserious or untalented in their lines of work.

More often than not, these certain upliftments have little to do with your personal strengths or skills.
And it's a thing with us generally. Those who become ultra successful feel others aren't as hardworking as them.
They beat their chests, boasting about their exploits.

As they should.
However, making judgement based on the exception is denigratory, and uncaring about the vast majority who try, try really hard, yet fail.
Imagine the many people who've been unsuccessful there, hear someone say, "An average Upwork freelancer makes 10k per year."

You belittle their efforts, by making them feel like failures; meanwhile life is just happening to them.
Life happens to a lot of us, or has happened.
Unfortunately, when it stops happening, we forget it happened, and start calling those it's happening to, "broke boys", etc