I don’t know who “The Left’ are where you live, but I can tell you that nobody I know with progressive views believes that Twitter is anything but a toxic hell-hole of inconsistent application of half-baked policies.
My suggestion to you is that it’s bad enough to “both sides,” an argument. Don’t “both sides” an argument with a hypothetical you just made up.
Plenty of Trump supporters have taken Twitter to task for fact-checking Trump but not other politicians. Or for fact-checking Trump now, but not in the past. These are legitimate arguments, because they refer to actual events.
Your argument is not worthy of the word “argument.” Please stick to comparing actual things that happened, involving actual people and companies, not hypothetical things that didn’t happen, combined with your interpretation of how people you will not name would or wouldn’t react.