What's convincing about it? The author doesn't even first verify that population sizes in each precinct/ward follow Benford's law before trying to apply it to the vote counts.

If you read the issues, someone already pointed out that the distribution is not wide enough to expect Benford's law to hold even in principle https://github.com/cjph8914/2020_benfords/issues/9

The underlying issue is that vote counts are tallied over regions whose size and population are chosen to fall into reasonable bounds, so they don't follow a power law like e.g. the size of cities.