The electoral college favors low population states. Republicans historically do well in low population states. In order to correct for this overrepresentation, Democrats need high voter turnout. So not voting or or voting third party depresses that high voter turnout Democrats need to win. This is why tankies and accelerationists spend so much time falsely conflating Kamala and Trump. They know they need to discourage as many people from voting for Kamala as possible to get Trump elected. So Vote!