Since the best clients such as, Mercedes, Audi, Vogue, ITC, UB Group, Naturals, etc. always use modeling agencies to find their models, you will be exposed to the best job opportunities. For example, if a particular model that a top client wants to hire is unavailable, you could be presented to that client as an alternative, and voila! You could get the booking. The mere fact that you are in the vicinity of agents, bookers, models, and clients will increase your job prospects by about a 1000 percent!
When you work with online clients you are really at the bottom of the barrel with respect to your job opportunities. You will most likely be doing non-paying modeling jobs and you will get no exposure at all to other clients. It’s really a dead-end proposition.