Why doesn't Biden come out swinging against Trump's obvious bias and call him a Putin Lover?

I think to say that Trump is in league with Putin would be the wrong take. He did praise Putin after the invasion, calling him 'smart' and 'genius.'

This is just one shyster admiring the shysterness of another. Trump would absolutely hate Putin if this has happened in his time in office.

Also, given that the war is going so badly for Russia, it really shows that Trump's judgement is lacking.

So Trump is a bullshitter who admires awful people. We knew that already but Trump should absolutely be mocked for getting this so badly wrong.

He probably figures there’s no use fighting a battle he already won

Biden is being presidential. Besides, Trump loves any kind of news coverage, so ignoring him and treating him as irrelevent bothers him more.

He didn't need to - as you said, it's "obvious."

It's not the time for that, most likely.

Plus, its really misleading to talk about Trump loving another human being.