Yeah, I that it is slow…
I googled a bit more and found that others have reported similar issues with the USB to SATA adapter
https://github.com/raspberrypi/linux/issues/3070
Bus 002 Device 002: ID 152d:0578 JMicron Technology Corp. / JMicron USA Technology Corp. JMS567 SATA 6Gb/s bridge
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
I guess I have to look for another one but not sure how to know which would be compatible.
Thanks again for the help, Joulinar!