Useful in sense of more loot but nothing absolutely unique locked behind a safe.
Terminals though, am not sure about. Have zero points in the hacking perk and for most part seem to get to all places fine, and few places found thus far with area locked behind terminal was accessible via key or access card you find usually on or near named npc nearby
However, as far as gated content - it does seem a decent number of PA is locked behind terminal access which so far I've had to skip.
Without needing to go into specifics, in general how useful or required is hacking throughout later stages of game in terms of gated content?
E.g. A locked safe is not gated content because its just more caps i can make, more increments of loot items found on shelf next to terminal. But PA only accessible via that one terminal is what i would say is gated content via hacking. Or areas you cant enter without hacking (this far not found one but spent most my 2 weeks settlement building, hardly any story or exploring beyond upper NA quarter of map.