I actually use crossbows for melee classes in case they need some range.
Switch weapon, shoot once, next turn they go in melee. (I only use if I have height advantage and don't want to move forward but still prefer crossbows over bows in that scenario).
Otherwise it's mainly for burst damage with specific skill that have a high damage multiplier (Snipe) especially if you go for a crit build but crit build are usually only good mid to late game, which is really not what we can see in the early access build.
Also the huntman skill increase height damages so maybe at higher level the difference is here. With the damage damage increase from the crossbow *2.20 with a snipe crit.
If you one shot a target with a crossbow but only bring one person to 10% health with a bow. Your second shot doesn't feel too useful right ?
OR, let's get crazy and do stupid build!
Ok, we make a summoner with max summoning ability. Your summons only care about you summon skill not any other stat. So you can put the stat points in Finesse and Wits (crit and better turn order).
Now the first turn you cart first you create your summon. Great!
Next turn you can apply a buff to your summon and shoot once, next turn another buff another shot...
You could actually make it a support character with heal, Magic shield, nether swap and teleport. All those cost only one point and don't scale any stat! So you can support and shoot your crossbow :p
Not to mention the summon at level 10 in Summoning looks super badass
