With the last challenger to Biden out of the race, without any unforeseen change (like one of these 75+ people facing great health downturns) it will be Trump versus Biden.
Trump is the incumbent and would probably gather the anti-establishment vote. Biden is a well known politician with 5 decades of experience, he was in politics when many boomers were in school bloomers.
It will be the old man's race this time, in a very difficult time for USA and the world. Coronavirus cases wreck the USA economy and cut short thousands of lives. This will obviously have great effect on the upcoming elections. It is a time where Trump is near his career highest or at his career's highest ratings but there are questions whether this will be enough to propel him to victory as there are concerns the pandemic recession and his handling of the Coronavirus would soon turn against him. Black voters have turned out in droves to support Biden at a time where their support could be crucial in swing states.
But the Coronavirus and the fallout on the economy and society is unlikely to be the sole issue. Immigration, climate change, medicare remain important issues for a lot of people as does the USA's image around the world and the USA's handling the relationship with China and an increasingly Hindu nationalist India.
And of course, the elections of 2020 are not just about the PotUS. Senate seats are up for grabs and the Democrats will try to wrest control of the senate from the Republicans. On the other hand, the Republicans will try to gain back the House from the Democrats or reduce the lead of the Democrats at least. While the PotUS has executive power, his powers within USA are limited by the Congress, so control of congress is crucial if the next president wants to push his agenda, whomever he may be.
It will be an interesting election.
EDIT: The Presidential election is over and while some contest the results, Biden has won the Electoral college.
But in USA's bicameral system, power doesn't lie in the hands of the PotUS; it is a not-too-powerful office by design, especially when it comes to domestic issues. While the President can make executive orders, they can be contested and shot down at the courts. And while the President of USA can appoint members to the cabinet or to the Supreme Court, the Senate needs to confirm them.
As such, who controls the senate is as important as to whom is president.
And who controls the senate will be decided in the runoff elections of January 5.