You also need to get “those” clients. And, to get those clients you need to show you can handle the job, which means a great portfolio and a staff to do the work. That will take time. Honestly I don’t see UE4’s quality level high enough for major presentations like Dbox and others do at the moment. That said as a design tool I think it’s got a good chance. Maybe down the road when things like reflections (mirrors, glass) no lightmaps, better lighting solutions etc. it can compete but right now there are too many problems.