Herman:
Upwork is not a "networking" tool in the sense that you describe.
It currently has no such feature.
You are correct in pointing out that this is a feature available on some other websites, but not on Upwork. Upwork will never offer all of the features that other sites offer, just as other sites will never offer all of the features that Upwork offers.
You are correct in pointing out that it is a violation of Upwork ToS for you to identify freelancers or clients on the Upwork platform, and then use OTHER MEANS (outside of Upwork) to contact them.
There ARE ways to communicate with other freelancers directly on Upwork.
Many Upwork freelancers "meet" each other by participating in the Community Forum. You are welcome to do that. (By which, I mean: You are welcome to participate in the Community Forum in a normal, expected way. You are NOT welcome to send private messages to freelancers who you don't know.)
Aside from that:
One way, which would NOT violate Upwork ToS in any way, would be for you to use the client aspect of your Upwork account to post a job, such as this:
"I am interested in meeting other freelancers who are experts in using Heatherton Website Builder Pro. If you are one of these expert, I will pay you $5 through this fixed-price job to fill out a questionnaire with the following questions: (a) How long have you been using this tool? (b) Are you certified? (c) What industry (or industries) do you primarily work in?"
Such a job would indeed allow you to meet other Upwork freelancers in your speciality. As long as you do not use these connections to hire them for off-platform work, this would be fine.
In a very real, practical sense, it is not Upwork's intention that its platform be used to "meet" freelancers, outside of posting jobs and hiring people.
You said that you would like to "meet" freelancers who work in other specialities. Yesterday I "met" a freelancer who is a Twilio expert - a specialty OUTSIDE of my own. I posted a job, hired a Twilio expert, and paid that freelancer through Upwork to teach me something.
If you want Upwork to create new a NEW FEATURE specifically for "meeting" freelancers without hiring them, then you would need to use the Community Forum to explain your idea and try to garner support for it.
