Hello I work for Unity (for now lol, we'll see)! I'd like to just say from my end of things we do actually do a solid amount of R&D. Just that a depressing amount of it either never sees the light of day, takes so long to release it has already been done better by someone else, or is unannounced with little to no documentation on release so it never gets visibility. The other thing to note is that Unity does a lot of non-game things that might not be that noticeable if you're just looking at it from a game making perspective, like our publicly known contracts we have to help train the military to "totally not kill people you guys"!