In all the years I've played, I don't think I've ever seen anyone fire a crossbow. Honestly.
The reloading is obviously the main issue, and I'm not sure how much can be done about that, because it pretty much was the historical drawback of crossbows. What was the advantage? It was way, way easier to hit your target with a crossbow. They were used specifically because it didn't take years of training to shoot properly. This does not appear to be reflected in the code.
Without getting into too many specifics, another issue is the fact that ranged damage in this game is very RNG. So is melee damage, granted, but you get to swing over and over every few seconds. With ranged skills, you have a chance to do double damage based on your skill level, and then damage is also further dependent on the location where you hit. Even a master archer won't do very much damage hitting someone in the leg on a non-crit roll. You can be a master archer and shoot someone in the neck for 90 damage, then for 11 in the leg on the next shot. This means that a ranged weapon that requires a long time to reload, and is usually only good for one shot, is just not dependable. If you're trying to use archery to kill somebody, you want to be able to get several shots off, hoping that one will roll double damage and hit the head/neck. This is how archery kills. You do not kill people with a non-crit shot to the arm. Well, unless it's with peraine.
Furthermore, crossbow bolts are bizarrely expensive. If you've run out and you really need more and you go to the bazaar to check, you'll be hard pressed to find any for less than 150 sid. If you've been around the block, you know where you can get unlimited arrows for like 15 sid each. Even if you have to deign to buy them from Salarr's in the bazaar, you can often get them for 50ish. Crossbow bolts cost so much that it's downright comical.
Now let's look at which classes might use a crossbow.
Enforcer: starts with crossbow (potential: master), has to branch master throw, doesn't get archery at all. A prime candidate, right? But this class also gets master sap/backstab. Under what possible circumstances would you prefer to shoot a crossbow? If you're only gonna get one shot, why not go all in on sap/backstab?
Raider: starts with archery (potential: master), has to branch crossbows. From archery. If you've already got high archery, why would you then switch to crossbows? By the time you branch the skills, you're already deadly with a bow, and raiders get the highest archery skill possible, so you're not branching crossbows until your archery skill says "master."
Fighter: starts with crossbows (master) and it branches into archery. Who has ever played a character that intends to use ranged combat extensively and chosen this class? Fighter is for Byn/Militia sergeants. If your ambition is to ride around the desert shooting people from a distance, you do not choose fighter. It would make no sense.
Soldier: starts with crossbows (master), it branches into archery. This is probably the class that's most likely to actually use crossbows, but have you ever seen it? Ever witnessed someone with class_soldier fire a crossbow? How do they even raise the skill? I mean, that brings us back to a discussion that should have taken place before: how do you raise crossbow in a manner that isn't nonsensical when crossbow bolts cost half the monthly wages of an AoD soldier, each? Yeah...
Scout: starts with archery (master) and it branches into crossbows. Same deal as the raider: once you've raised archery that high, there's really no reason to switch to crossbows, train the skill up from scratch, and arrive at a result that doesn't even seem as good.
Stalker: starts with archery and crossbows (advanced) which, yet again, why don't you just use a bow which can shoot much faster and does not appear to do significantly less damage? And you can ride to the [self-redacted place we all know about] to buy unlimited arrows for pocket change?
Long story short, crossbows would need to do like two or three times as much damage as archery before it was genuinely worth considering. I'll admit that I have no idea if it does, but the fact that I have legitimately never witnessed a player character use a crossbow kind of suggests to me that it doesn't do that. It simply appears to be a dead skill.
Maybe double the chance to hit with crossbows, and the chance to land a critical hit for double damage, to reflect the fact that crossbows were historically used because they required little training compared to bows. That'd be an idea. On the other hand, that would make it much harder to actually raise the skill, and as we all know, the worth of many skills is based on the difficulty of raising them due to arbitrary code quirks. A tale as old as Armageddon.