Finding target audience

CGtrader already receives a great deal of traffic, by now almost every CG artist knows this place exists, so I don't think the problem is regarded to traffic or people not finding your work. Most of your models already receive views and you can increase this using social media and popular forums and CG art portals.

You currently convert less to sales partially for following reason (my personal theory, do not take for absolute reality).

If I look at you models they all look a bit same style and same thing, (do not understand me wrong they look very good). But I suppose they appeal to people hoe like/need that specific thing or stile, so maybe try to diversify and create different things and stiles to appeal to bigger audience.

Sci-fi is already a niche, so if you target a niche within that niche, then market segment gets very small (you provide only drones and only in specific style).

Also It looks like you are using a set of kitbash models that get used in most of the designs, wish is good but maybe put that set online for people hoe want to design things themselves.
(that would appeal to other possible audience and expand market segment a little bit)

Also If you create a kitbash set then it is good to create some nice models with it to showcase the potential of the set, but if you keep using it to generate end products then they will lose value and the value of the set itself will also drop.

So best to keep creating new sets and make models of completely divers nature (not to many) to showcase widespread possibility's of the sets.

You can also use the created models as bundle packagers (for model sets) or sell them separate.

If you can create remarkable art with the kits (like you already do) then it will be more easy to get noticed on places like (https://www.artstation.com/) or (http://polycount.com/categories).
But if it get to many of the same things then it will be harder to stay noticed.

In a nutshell, you need to get to broader audience by delivering things that appeal to broader audience. Maybe create divers products for different types of people and the different needs.

If you want to stay in Sci-fi category you can for example produce, texture packs, UI elements, 3D kitbash sets, environment elements, space ship elements, cockpits, facility elements, robot parts, gun turrets, character armor elements, etc.

I hope these personal thoughts can help you in some way.