Of course, nowadays there is little resemblance between portage and the FreeBSD ports, after a few decades of separate evolution.
When I switched to Gentoo (in 2003), among the Linux distributions (after previously using many others, like Slackware, Redhat, Suse, Mandrake etc.), I had already used for many years (since around 1995) the FreeBSD ports, so this was what attracted me to Gentoo, its software package system and its documentation, both of which had a level of quality comparable with FreeBSD and much superior to what the other Linux distributions provided at that time.
Of course, nowadays there is little resemblance between portage and the FreeBSD ports, after a few decades of separate evolution.
When I switched to Gentoo (in 2003), among the Linux distributions (after previously using many others, like Slackware, Redhat, Suse, Mandrake etc.), I had already used for many years (since around 1995) the FreeBSD ports, so this was what attracted me to Gentoo, its software package system and its documentation, both of which had a level of quality comparable with FreeBSD and much superior to what the other Linux distributions provided at that time.