I’m advocating supporting a third party candidate to force the Democrats to answer to the left.
I don't really get the mechanism by which you are suggesting this would happen.
All the support for Bernie put no visible pressure on Dems, all the support for Nader didn't either. Jill Stein did nothing but help Republicans when she ran, and now she's helping Cornell West do the same.
Your vote maintains the Status Quo.
Only in that it doesn't push things to the right, which a vote for any third party effectively does in today's environment.
Why would Democrats offer ranked choice voting
I don't claim to have a roadmap to ranked choice voting, but whatever slim chance we have of getting that done at some point is still far more realistic than the idea that voting green is going to have any impact other than putting an R in the whitehouse again.
However much improvement the Dems may need, they aren't actively rolling us backwards. I can't fathom how anyone does that calculus and comes to a different conclusion in 2023, after witnessing 2016 and 2020.