Why didn't the Blue Wave happen?

Biden will probably win but only just. He badly underscored his polling, as did the Democrats nationally.

Im not interested in Trumpian conspiracy theories about the polls and I get that Biden did win the popular vote on a high turnout. Even so...

Trump increased both his vote share and amount. The Lincoln Project made huge efforts to try and shift Conservatives to Biden but it didn't really materialise. In spite of all the things Trump has said and done, he increased his votes with minorities. In spite of his awful covid handling, he is still favoured by people who prioritise the economy.

Im interested in what people think.