It's a blatant lie and bullshit. A github MR can be 5Mb size and my laptop has 64Gb RAM (swappable 3x of that to SSD if really needed). There's NO need for progressive loading there.

Another example is filtered goods at the local electronics store webfront. Progressive loading without ability to go directly to page 7 wastes my time if I know that what I need is there as each load of 10 items takes time. But of course this pattern increases some shitty OKR in time-spent-on-website. Hate this.