The problem (for me anyway) is that much of the circumstantial evidence being floated this past year isn't even really circumstantial evidence - it's speculative inference. And much of the circumstantial evidence that does exist supports more than one inference, and not all of those inferences lead to a foregone conclusion of guilt. There's a lot of leading narrative out there.
Yes, many of the elements brought forth have seemed suspicious based on their framing and presentation. Many of the elements could also have been presented in a different framing and seemed innocuous. And many of the elements brought forth haven't been brought forth in an objective fashion.
I agree that Trump Jr. meeting with Vesnilwhatshername with the intent of receiving damaging information about Clinton was unethical. It may or may not have been illegal - I'm not a lawyer, and legal opinion seems to show less consensus that I would like in order to form a conclusion.
But it has been presented with purposeful framing: Russian lawyer with some degree of association with Russian government offered dirt = soliciting something of value from a foreign government = evidence of active collusion/conspiracy.
What raises more skepticism in me is the double standard in play here. Democrats literally paid a foreign intelligence operative to dig up dirt about Trump = somehow not soliciting something of value from a foreign government = no problems, perfectly acceptable.
There's always a fairly high likelihood that there is information in here that I don't know. I don't drool over the latest news tidbit, and I actually have a busy life outside of the current political drama

. I simply haven't been able to fathom the distinction being used to differentiate these situations from one another that isn't more easily explainable as simple partisanship.