In 2020, Biden stayed in his basement and let Trump be the center of attention, believing that the incumbent would destroy himself. It worked. The public got tired of Trump’s antics, particularly with regard to the pandemic, and voted him out.
The plan is the same this year. The problem is that Trump–completely inadvertently, as he loves being the center of attention–is avoiding public scrutiny; he only makes news through his almost daily courtroom martyrdoms. Not debating, and so not subjecting his ideas to criticism, also helps. That makes the election a referendum on Biden, not him.
This will change. The courtroom dramas help Trump with the base, but probably not with swing voters. In any event, his behavior and unconventional policy ideas will get a lot more attention once the primaries are over and the MSM starts to focus on him rather than DeSantis and Haley. If the election is a referendum on him, not Biden, he will lose.