Depends. As example, Masters of Raana. Can`t say I like it, but I can admit the productivity of dev. Last year has a decent progress.Even if Inno wasn't a lazy hack, the planned game world is simply too large to be finished by a small team. You'd keep getting bogged down with NPCs and events in each zone
Basically it's all about passion with a bit of structured approach. So long ppl want to do it and don`t create too much problems for themself, they can do it.