A bit off topic but it has to do with R&D, how twitter invest almost 2B in R&D and there are no visible new features with that investment (well this year it see

A bit off topic but it has to do with R&D, how twitter invest almost 2B in R&D and there are no visible new features with that investment (well this year it seems that they started to add new features, but they doesn't worth 2B, edit tweet, I saw something with gifs?). I'm not a twitter user, so I cannot 100% sure but to me it sees like the same twitter back en 2010 or 2012 (when I first used twitter. So my questions, is the R&D money invested to keep engineers happy? I mean they can for sure experiment there without any worries.