Are they running T-55s as main battle tanks against Abrams and Leopards?

There isn't much in the way of tank battles at this point. But they are still fielding them, and we are still getting visually confirmed losses of such equipment.

...what does the casualty disparity tell you about Putin’s willingness to absorb losses?

Oh, I have no doubt he doesn't give a crap. He's willing to absorb as many losses as he has to. It's just pawns to be sacrificed. Never implied anything else. But he doesn't operate in a vacuum. He has to deal with domestic politics, protests and discontent, and all that other fun stuff. He can't win unless he ramps up his war-time manufacturing. In doing that, he'll feed the discontent. He promised a swift victory, and he didn't deliver.

War and defense economics aren't as simple as "more dudes", and actually have a stronger effect on the outcome of a war.

As for the rest of your rant, you're just wrong. If you consult more than the talking heads of FOX, you'd know more. Just as a quick example, here's CSIS:

csis.org - Russias battlefield woes ukraine

That's just one source I had handy. There are a lot more out there. And then there are commentators that distill those disparate sources (with citations!) into easily digestible essays.

You are correct that the front lines aren't moving much. But you draw all the wrong conclusions from that.

As for HRC, I don't know or care what she said. She's history now. Sure, she was the smartest person in whatever room she walked into. But she's done. We've all moved past her. Just some folks in the RW can't seem to let her go for some reason.