For video decoding on the GPU, processing on the same GPU memory in place and then displaying takes significantly less work than decoding on the CPU copying to the GPU and doing the rest their and most of the time is in the copy.
david@liqueur:~ $ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/nvme0n1p2 13G 4.8G 7.3G 40% /
david@liqueur:~ $ swapon -s
Filename Type Size Used Priority
/var/swap file 204784 0 -2
Sure the adapter introduce a cost, but even a used Optane drive is going to have better reliability, in addition to the mentioned performance, than a new SDcard; so pay $5.