I'm assuming h2h polls with Trump aren't very useful
1. This early, any head-to-head polls fail to predict how the economy, the foreign scene, and the level of domestic tranquility will be. At this stage in the Presidencies of Herbert Hoover and Jimmy Carter, both seemed to have smooth sailing to re-election.
2. As the 2020 election shows, Biden will need an outright majority with which to get elected. Democrats run up huge margins in states that leave no mystery about how they will go -- CA, NY, MA, MD, IL, NJ, WA, NM, and CO -- while a Republican can win by working margins in swing states. Biden is still short of a full majority, and he will need at least 51% to defeat the Republican.
3. We do not know what the match-up will be.
This said...
1. 36% support for a former President is historically low. Donald Trump is a known quantity, and 36% support at this stage from someone well-known is putrid. We have seen few polls about an electoral assessment of Donald Trump since January 6, and this is the first that I recall of a Biden-Trump rematch since the election.
2. In my experience the undecided swing ineffectively to the eventual loser. That is 16%, and even if Trump gets 11% of the 16% he loses. That would be a 51-47 edge for Joe Biden, which he would need for winning three of Michigan, Pennsylvania, Wisconsin, Arizona, Georgia, North Carolina, and Florida. Getting 68% of a vote outstanding is possible if one is looking at votes coming in from the largest city in any one of those states. We know why. With undecided voters not identifiable by partisan identity, getting 68% is almost always a pipe dream.
3. Giver me these numbers in 2024 and Biden wins. Like an incumbent, Trump will be running on his record -- or running away from it. If a pol runs away from one's record, then the record will chase him down like an angry dog, catch up with him, and overpower and maul him. If he runs on his record... well, President Biden already has some positive achievements. I do not expect him to kick over any hornet's nest.
4. Incumbents usually shape the political debate. An example was that Donald Trump and the GOP successfully offered campaign pitches that claimed that Joe Biden would be soft on socialist regimes in Cuba and Venezuela (those probably won Florida) and a campaign ad that threatened economic failure if Americans voted their conscience and their values instead of voting for Donald Trump and his economic agenda (which played in Michigan, as I know... and I am guessing elsewhere). You may hate Donald Trump and the GOP, those ads said, but if you know what is best for you you will vote Republicans.