Google has 88k employees and had a $32B revenue last quarter. Let's assume 25% of employees are R&D, each paid $250k/y: Google would spend $5.5B a year on R&D, or 4.2% of revenues ; not quite a "large portion of their capital".
Also, that's a rather low estimate for average compensation for devs at Google. If, as you mentioned elsewhere, the 25% number is a purposeful overestimate, then combining it with an underestimate of compensation means that your total number is murky; it could easily be a drastic over- or under-estimate.
That said, 25% is also an underestimate - in 2016 Google reported that ~38% of full-time employees were in R&D. So it sounds like you think you're overestimating how much they spend on R&D, but in fact you're way underestimating it.
(But let's not talk about the executives you never see, coming in through private entrances straight from their private landing strips and making x1,000 your salary.)
25% of people are researchers at Google? Are you saying that's what you think it is at the moment or hypothetically? Research is a tiny tiny proportion of Google's work.
"Production" is something like building the same factory that was built thousands of times before, to fabricate the same widgets that were fully designed by an R&D team.
The actual top researchers at a place like Google would be making way more than $250k.