In terms of magnification, yes, but there are also many other variables that can be relevant, so I guess it's good to have multiple cheap designs to choose from, depending on the goal and circumstances. For example Foldscope seems to be using ball lens, which indeed gives higher magnification, but probably also suffers more from aberration, may be trickier to fix firmly and precisely into the microscope housing compared to the lens that are already created on a flat plate, etc., so for those tasks where lower magnification is sufficient or preferred the droplet lens might sometimes be more suitable.