[peterangular]

It's an over-generalization and I'll throw my own anecdata in here from ecommerce: I've seen MAJOR improvements with conversions when I can get something from a 1s load-time down to <250ms. I don't have any published studies out there on this but you can definitely find TONS of data on faster load increasing customer interaction/conversions.

Specifically, it's an interface-to-interface thing as much as a first load experience... if a customer can browse my stores with near-instant loading of product pages (or maybe even pre-loaded) they are more likely to look at more products. If they're more likely to look at more products, they're more likely to buy, etc etc. Sure 750ms doesn't SEEM like much, but what about someone who's shopping for a formal dress? They may be looking at 20+ unique SKUs within a shopping experience so take 20 * 750ms and there ya go.

We don't control things like network conditions, etc. and even in 2020 we must be respectful to the end client in regards to transmitted data to run an experience.

I know I didn't link to any studies here so it's all moot, but I'm just sharing my in-industry experience with optimization to illustrate that lots of people don't settle for "90% of the time <1s is good enough".