Migration assistant: 'Preparing for the transfer' for hours

Hi, my mbp 16" from 2019 was using Catalina up until next week when I decided to update it to Monterey, it bricked my computer and had to be serviced and all its data got wiped out.

Now im trying to restore all of it from the time machine, a 4TB external hard drive but the data from should be 400GB max so there's space enough to be copied. I started the migration assistant, it recognized the backup, I started the process and it has been for a few hours in 'preparing to transfer the user documents' stage. The bar is moving from one side to the other, so i assume it's not stuck but im not sure how much time it can spend in this phase.

I remember doing the same thing a couple years ago from an older mac to this one and it was much much faster than it is now.

Is there any other way to recover the files without relying on apple's software. I know the old versions have folders and stuff but im not sure it'd be an easy task to sort everything by hand.

Thank you very much