I think the main thing is that we haven't seen what he might do now that he knows for sure that he's (by default) headed for a lifetime in jail.
It seems that before the arrest, he was pretty delusional / "high on his own supply" and believed he was going to somehow talk his way out of trouble, as he'd ostensibly been doing for so long.
So the thought experiment now is: do we believe that there's anything nefarious that he could do now, that he'd stopped himself from doing back when he was still trying to maintain an illusion?
For example, he could have various wallet private keys (secretly?) memorized [1], and could take steps to move the funds to new wallets.
TBH the idea that his (fiat) transactions are limited to $1k is a little laughable for someone who until recently, and perhaps still, has access to billions in crypto.
Of course, that's what he wants me to think. I'm ready to learn that my take is too naive. But so far, evidence of a bigger plot is missing for me.
[1] https://en.wikipedia.org/wiki/Jack_Abramoff#Post-release_act...