Perhaps what is really important is to look for other platforms that offer you new niches, not necessarily for different products, but rather to look for platforms that have other types of buyers; more casual, more serious, more wealthy or less wealthy, some specific area...
I mean that the person who buys you something here is probably the same as in another platform that "looks like" cgtrader. So you will not get new sales, but you will scatter sales between the different platforms you are on.
So if you think that your models can be sold to different niches than those that can be found in cgtrader, do not hesitate to look for them and create a store there, but otherwise, do not waste time because the only thing you will do is multiply the work.
Although this is my personal opinion, so take it as such! all the best!