VMS had four different file types out of the box: serial with carriage-return carriage control, serial with FORTRAN carriage control, random-access, and ISAM (indexed-sequential access model). Three of those worked as well from a bank of open-reel TM03 devices or TU-58 carts as they did from a cluster of DECNET drives.
You could, of course, extend those models by plugging in to the rab$, fab$, and xab$ layers or write your own from scratch using the sys$ layer.
Unix, in contrast, had only the random-access file model. You could use just that file model to build any of the other types in userspace, but to talk to a tape drive you had to use the tape archive (tar) utility.
It's just the usual tradeoff about where you draw the line between a solution and a tool.
You could, of course, extend those models by plugging in to the rab$, fab$, and xab$ layers or write your own from scratch using the sys$ layer.
Unix, in contrast, had only the random-access file model. You could use just that file model to build any of the other types in userspace, but to talk to a tape drive you had to use the tape archive (tar) utility.
It's just the usual tradeoff about where you draw the line between a solution and a tool.