Which would lead to inflation right? Leading to these bonds having even lower value?

Showing that you don’t want to be the last one out since either the risk or inflation hits you.

>The fed would almost certainly intervene aggressively resuming large scale QE to buy up treasuries and stabilize yields.

Indeed and QE is a major inflationary pressure.

What if the fed ceases to exist soon?

It won't cease to exist, it will just answer to the orangefuhrer like most other US government agencies already do.

we've played this game before

In the past, the game was as played with the additional benefit of foreign bondholders and currency reserves slowing the overall velocity of money. The rest of the world has heen quietly blunting the inflationary effects of printing USD.

Most Americans - this administration included - don't know how good they have had it, and are throwing it all away due to avarice.

don't worry, because financial ouroboros