They do help with promotion by giving "top rated" and "raising talent" badges and work history. Hard to say how much value and leverage it really gives and whether it worths all the downsides.
work history is github or linkedin or gitlab to show your the real examples. But the ideas around connects, fees, it's really unsuitable to deal with the platform. Even the job post could be dead because the author left the platform and found the freelancer in the other place. and as result the connect points could not be restored. at least I had such experience by buying connects to apply and then I skipped this idea and didn't come back.