Its plausible that Bernie might have been successful on his own in recent elections had he made his own party considering how much support he got in the DNC’s primaries despite being a technical independent.
It’s not impossible for a new party to compete successfully, just very difficult.
If it took Imran Khan 20 years to create a populist party worthy of rivaling the military establishment in Pakistan who runs an actual fraudulent election every season, surely America can create a grassroots party worthy of dethroning the GOP and DNC.
Repeatedly voting those two parties and expecting ranked choice voting to become a thing is the real fallacy here. Neither party would pass legislation that weakens their stronghold on elections.