I don't see why a commercial company striving for revenue and growth would follow the free/open source model.
draw.io app by https://www.diagrams.net/about.html is free and open source (https://github.com/jgraph). Either the authors are volunteers or I can't figure out what their business model is.
https://www.myfitnesspal.com/ received $18M in venture capital funding and has 18 open job position which I'd guess means over 100 employees. "UnderArmour sells MyFitnessPal for $345 million" https://www.zdnet.com/article/underarmour-sells-myfitnesspal...