He is not centrist:
https://joebiden.com/joes-vision/
Reading through his list, I see trillions (plural for a reason) of dollars worth of proposals and no way to pay for them.
For example, he wants to put Bidencare on top of Obamacare by creating another insurance company (besides CMS) that people can buy insurance from. It's not far removed from universal health care the liberals are pushing. Just different in name only, really.
Another example is what he wants to do in regards to guns. He wants to let people sue gun manufacturers. That's like suing GE because some idiot got sucked into the intake of a running jet engine. No, no one sued GE because of that. Limiting "high capacity magazines" is a non-starter because anyone that used a firearm in a self-defense situation knows regular capacity is hardly enough. He wants to create a registry of property for sales made decades ago; another non-starter. He wants to create a buy back program like Australia did; Biden loves spending money that isn't his. Oh, and best one? Literally limit people's right to firearm property by limiting the number they can own; a direct violation of the 2nd amendment and 4th amendment. I'm only 15% down the page too! These proposals are downright draconian, not centrist at all.
Trump is more centrist than Biden. Remember, Trump was a Democrat until the party went far left (two examples of that above).