Mine (herding breeds and mixes) have all eventually outgrown it, but often not until 5-7 years old. We have multiple dogs, so sometimes it depends on the current personalities too—dog x will start spats with dog y resource guarding crumbs, so one must always be locked up when we are out, but dog z is fine with everyone and gets free privileges always.

They are crated during a typical full work day out of necessity and are fine—I just make sure to really work them (training, hikes, swim, classes) before or after work, not just give them yard access.

Just get used to it. And get rid of the guilt of crating your dog for more then 2-3 hours - it's ok for a dog to be in crate for 6-8 hours occasionally assuming the dog has ability to fulfill his need of running/sniffing/playing during the rest of the time. It was normal in our family pre-covid working FT in the office:staggered schedules, dog walker drop-ins, long walks/runs in the evening, hikes on weekends. That's the only way to have a dog then, had to crate our working line pup until he was 6 yo (then COVID hit and changed everything)

Our previous rescue was a pretty anxious, busy dog, but we found out that he did totally fine home alone if he had access to our bed and could just nap on our pillows while we were away. He probably had confinement anxiety and only light separation anxiety.

Our new rescue is a very smart, busy dog who we have to crate when we're not home. He's a herding/hunting mix, so we shouldn't be surprised. Left to his own devices, he will find infinite ways to entertain himself, including successful experiments with unlocking doors. I don't know if he actually wanted to escape or just sees the deadbolt as one more puzzle to solve. We are in a small, open-layout house, and we don't have a space like a mudroom or a laundry room where we could create a safe space for him.

Anyway, we're fine crating him, but it means that we don't leave him long because it seems cruel to do it for stretches longer than 2-3 hours and he definitely gets up to antics in his crate with interesting puzzles, safe treats, and safe toys. We give him a great mix of sniffing time, exercise, play, and work when he is not in his crate, and worked hard to find the balance between tired and exhausted (like a toddler, he behaves badly when he is overtired). We also had to put extra locks on his crate, because he figured out how to unlock it from the inside- I'm pretty stressed about what would happen in a fire or other dangerous situation, but the risks he poses to himself uncrated are far more tangible.

He's 18 months old. It's been so longer since I had a younger dog (our old dog died at 14!). Do dogs who require this kind of containment and supervision grow out of this, or should we get used to it?