Because it is rare that they go above 1080p. In mac's chrome, they just go to 720p max, which is way below industry standard. And the worst thing is there is no option to set the quality even if I am ready to handle some pauses in the video if my network speed can't catch up(which it can, just that they err on the safer side)
maybe low for western standards, but the majority of devices worldwide cannot display higher resolutions.
hek, even new budget phones today rarely exceed 720p.
anecdote: worked at a cinema and we cast 720p onto the big canvas (10meters wide) because people would not notice a difference to anything higher. overall bitrate and quality of encoding are mostly the deciding factors.
My favorite unpopular opinion to share (I work in video) is that 99% of viewers don't care about resolution above 720p. Other encoding and playback characteristics are just way more important if you aren't building for videophiles.
Netflix limiting mac chrome playback to 720p is case in point if true (though I've never heard this). What % of their "high-end" users is this? My macbook has more than five times as many pixels than 720p... I've never noticed this, and Netflix surely recognizes that they don't stand to gain much by streaming higher resolution to most users.
Netflix, of course, does build for videophiles, but I still hold my conviction to the extent that I constantly question the priority of work to make something 1080p or 4K.
I will certainly concede that VR use cases need higher than 720p resolution.