system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] What was the importance of the Hoth base? Wouldnt it have made sense to stay mobile with no permanent structures?
gpt
Ships need maintenance and crews need offship time.  A lot of the ships in the rebel fleet are medium sized.  They're small enough you don't want to spend excessive amounts of time in space aboard one and aren't built for extended voyages, but at the same time they're too big to reasonably fit into your standard starship hanger.

Sure, Home-1 or the other really big capital ships might hold them, but those ships are rare and you don't want to be filling fighter hangers with freighters just so you can perform your waste disposal system's regular maintenance.

A planetary base is perfect for this sort of ship.  They're already intended to land and takeoff, and on a planet you're not limited by volume as much.  Finally, most humanoids in the alliance are accustomed to working in gravity.  Zero-g work is just much more time consuming for them. And that's all not to mention it gives more room for your personnel.  Hoth contained a sizeable amount of infantry as well, and you don't want your military men stuffed into a freight hull for too long, they get bored and out of shape.  Morale and effectiveness will plummet fast.

So really, there's a lot of good reasons to have a planetary base.  Hoth was selected because it seemed like a good one.  Way off the beaten tracks and not someplace you'd ever expect anyone to *want* to live.  Vader's willingness to indiscriminately plaster the universe with probe droids despite the cost just turned out to be a good counter.  There's some that say he was guided by the dark side of the force to the location as well.