You seem to be relying on polls, so I posted a poll to show you that Biden with a 40% approval rating was technically ahead of Trump with a 39.7% approval rating. I also showed you how Trump was the front runner amongst Republicans using the same source. So the republican front runner is behind the incumbent. Technically.
I however dont trust polls. It has always been broken. It misled in 2016, when every poll showed Hillary winning. Then in 2020 it showed Biden having a large lead over Trump but elections showed it was much closer than that.
So if the polling today is showing you that Trump and Biden are neck and neck....well am not buying it. Especially with how Trump at his height of popularity was voted out, and is currently in legal turmoil and deeply more unpopular to the extent that many former Trump supporters are disillusioned with him.
The bottom line is Biden is the incumbent. Incumbents are and have historically been hard to beat and the only time in recent times they have been beaten is when the challenger was immensely more popular and charismatic like Reagan, Clinton or appeared more sane, like Biden. In Trump's case, we have an insane guy voted out at the height of his popularity, currently facing all kinds of legal trouble, and still polling below Biden. Putting all that together, it tells me that, come 2024, Biden will most likely have the upper hand. (And the orange clown will most likely be in orange overalls lol).