"low" in a way is a relative term. and I have seen people confuse it with a dead market. for example there are many exchanges with low volumes out there which are working fine and I have had the best experiences of my trading on those platforms whereas I always had bad experiences with big exchanges because of a lot of issues including lack of support, slow servers,...
"low" volume in my opinion is not a problem as long as their markets are not dead which means as long as there are people trading on these platforms in those markets, it will be fine.

and to answer your question as it was mentioned for me the security and trust is the most important factors.