I know it seems super annoying to many players but in a lot of ways it's the lesser of two evils.

You can always filter out sextants, but if they chose to list in chaos, they would either price their compasses at bulk prices and be totally invisible to anyone seeking bulk compasses, or they would be the cheapest option, flood the first like 20 entries each on the trade site since POE-Trade lists them as individual items and then the sellers would refuse to sell to you unless you bought bulk.

This is kind of how beasts work at the moment and buying a single beast can be a pain when the trade site can only show 3 sellers who are undercutting all the singles sales and then demanding minimum 10 beasts for a sale.

Some QoL for compass trading would go a long way though