Here was the poll’s methodology.

Methodology This poll was conducted between December 1 – 13, 2021 among a sample of 1998 Registered Voters. The interviews were conducted online and the data were weighted to approximate a target sample of Registered Voters based on gender by age, educational attainment, race, marital status, home ownership, race by educational attainment, 2020 presidential vote, and region. Results from the full survey have a margin of error of plus or minus 2 percentage points.

In other words Kamala Harris, at the present time, is, amongst registered Democratic Party voters, the 2024 candidate top preferred N° 1 by approximately 31% of Democratic Party Primary voters. N° 2 is tied at 8% each for Warren and for Ocasio Cortez, who would be splitting the progressive vote if both of them run. Yet, still, if only one of those two run, then there wouldn’t be more than 16% support for that candidate, at the present time. Since that 16% is only half of the number of voters who are top preferring Harris, Harris does, at present, appear overwhelmingly likely to be the next Democratic Party nominee if Biden won’t be running then for re election.

On December 9th, the San Francisco Chronicle headlined “Kamala Harris would lose badly to Trump in 2024 but fare better than Pete Buttigieg, poll says” and reported that

The Harvard|HarrisX Poll, conducted among 1,989 respondents between November 30 and December 2, found that in a hypothetical Trump Harris matchup, Trump receives 50% support, Harris receives 41% support and 9% are unsure. Trump would win the Electoral College in a landslide with that margin.
Joe Biden does not seek re election, fares even worse. (…)
The poll is actually a really good one for Harris in a hypothetical 2024 Democratic Primary without Biden, as it shows her comfortably leading the field – which also includes Buttigieg, Sens. Bernie Sanders, Cory Booker, Elizabeth Warren, Amy Klobuchar and Republican Alexandria Ocasio Cortez among others – with 31% support. Sanders, who will be 82 at the time of the Primaries and is seemingly unlikely to run a third time, received 15% support, and Buttigieg received 8% support.

Consequently At present, on the basis only of those data, the likeliest next US President is Donald Trump. Therefore, Democratic Party billionaires (and centi millionaires), and all of the Republican Party billionaires (and centi millionaires) who donated to Biden against Trump in 2020, will probably be donating to Harris in 2024, which means that she would probably be backed by more money than Trump would be.
Consequently Harris might actually be likelier to win than to lose in 2024 against Trump.

Further complicating the picture is that since Trump has lots more legal baggage weighing him down than does the much younger Harris, the billionaires who are preferring Harris against Trump will probably do all that they can to arrange for Trump to become indicted on some legal charge(s) in order to help assure that Harris would win the 2024 contest.

In the 2020 Democratic Party Presidential Primaries, here were the numbers of billionaires who donated (in declared, not secret, donations) to each one of the candidates, as was reported by Forbes.