So Biden's numbers are fairly stable, all he's gotta do is perform some trick to make indies happy and he's walking in high cotton again...
Basically, we gotta sit on our hands for 6 months, everything happening now will be replaced with whatever is happening then and will point more closely to the election results.
I don't think it's a matter of getting indie voters to switch parties so much as which indies get off the couch. Left leaners tend to be kind of ho-hum about midterms.
Independents have made up approximately 40%, give or take a point or two of the electorate for the last 10 years. Yet they only make up 25% of those who actually vote. In 2020 republicans made up 27% of the electorate, Democrats 31%, yet Republicans made up 35% of those who voted, Democrats 37% while independents made up 26%
I think one of the main reasons is Republicans and Democrats own the horses in the race, the candidates. Independents are basically bystanders or perhaps causal fans. Republicans and Democrats choose who they nominate, most independents have no say unless they live in open primary states.
But back to your point. What the numbers are today are basically meaningless come Nov 2022. If Biden and company had these numbers in August and September 2022, they'd be in trouble. But today, way too much time left. No one knows what will happen or what unforeseen event will occur that could change or turn the whole apple cart upside down.
This doesn't take away from independents deciding elections though. neither party's base is big enough to do that. Democrats enter an election, nationally, with a 3-4 point advantage in party affiliation. But independents can wipe that advantage out in a hurry.