While that's the original meaning of the acronym, it was generalized into a virtual machine, so it has come far from being able to just filter packets.
Just one place early on this page using the full words instead of the acronym would have done the job. Such a small change would make such an immense difference for outsiders.
More details under "BPF kernel internals" here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...