Can you elaborate on what you mean by "A lab that uses some learning-based method will likely be limited to just one or two people (responsible for data acquisition, feature engineering, evaluation, etc.)" ? I know a bunch of labs that apply machine learning to specific tasks, and the parts you list each can easily take up multiple people for years for a single task - not counting data acquisition, because data is definitely not "extremely finite", you need lots of quality data, and improving data is something that always gets improvements and can easily eat up more manpower than you can have budget, no matter what that budget is.
