Another thing I'd like to mention about carriers: they have been extremely useful for expeditions. Especially for exploration surveys where people scan given areas, but also for waypoint-based tours. Specifically, it's about keeping participants together: it's much easier to organise that when there's a mobile base of operations, and people who might fall behind can still dock on the carrier when it's time to move. Not to mention that when there are specific systems to explore, people might want to spend time on those instead of travelling the whole way in their own ship. Or hey, if there are events held, then bringing along carriers can ensure that most everybody can get to the event locations on time.
Personally, I prefer the afk nature of carrier travel, but well, I'm almost at 90,000 jumps, so no surprises there.
Also, group shots in carrier bars.
Like this.
Oh, one other thing. Sure, you can always fly out to someone else's anchored carrier and transfer your ships there, but if you do that with many (and expensive) ships, the cost of buying enough tritium to do it with your own carrier can well be cheaper. Not to mention there's no waiting for several days of transfer time.
Then there was another subject that I wanted to reply to, but off-topic:
3A shield generator (probably don't need anything better)
Probably, but the AspX's shield characteristics are bad, and a 3A shield generator will give you, what, 130-160 MJ fully engineered? With the AspX, that won't hold up against anything more than light collisions, so be extra careful.
And well, collisions always happen the way one least expects them. Once, when I was making shots with the external camera with my Courier hovering above something, I accidentally hit boost when I came out, and even with my Courier's strong shields, I was left with something like 14% hull. Another time, my joystick suddenly failed as I was flying a Clipper at low altitude too, and I couldn't replug it in time. One of the most well-known explorers got sent to the rebuy screen because he boosted away from a NSP - only to have a pod suddenly fly in front of him. He was flying a cardboard build, the pod was invincible. The stories could go on.
It's always what you don't expect, and nobody can avoid an accident forever. When that happens, a strong shield generator will be the difference between surviving it and limping back to the nearest repair shop, or staring at the rebuy screen.