I am well aware of the math on that. Also, switching to faster infra can be a surprising benefit to your revenue, by the way, if it makes your app feel nicer.
The thing is, most features, particularly later in the life of a company, don't have an easy-to-measure revenue impact, and I suspect that many features are actually worth $0 of revenue. However, they cost money to implement (both in engineering time and infra), making them very much net negative value propositions. This is why Facebook and Google can cut tons of staff and lose nothing off their revenue number.
Also, there's a bit of a gambling mentality here which is that a feature could be worth effectively infinite revenue (ie it could be the thing that gives you PMF), so it's always worth doing over things with known, bounded impact on your bottom line. However, improving your efficiency gives you more cracks at finding good features before you run out of money.
The thing is, most features, particularly later in the life of a company, don't have an easy-to-measure revenue impact, and I suspect that many features are actually worth $0 of revenue. However, they cost money to implement (both in engineering time and infra), making them very much net negative value propositions. This is why Facebook and Google can cut tons of staff and lose nothing off their revenue number.
Also, there's a bit of a gambling mentality here which is that a feature could be worth effectively infinite revenue (ie it could be the thing that gives you PMF), so it's always worth doing over things with known, bounded impact on your bottom line. However, improving your efficiency gives you more cracks at finding good features before you run out of money.