Many people don’t realize but several functionalities are available to blueprints via C++ plugins which are part of the engine. All someone need to be successful on a blueprint only game is to have in their arsenal the best plugins for the correct tasks in the game. If you run into a trouble implementing something into blueprint, then you could ask in the forums (if not a project secret) on how to achieve it in blueprint or if it would be better have it as a plugin. Plugins, if done right, will expose everything you need to the blueprints.
My opinion is that yes, you can be successful !