Little late, but I think I see how we have such different experiences. Assuming other comments are right, and Reddit's pulling pretty much entirely from cache, you probably just scroll longer than I do - long enough to run out of the first ~1000 (cached) posts, and hit uncached items.
You'd get timeouts, and I'd never see them - despite being West Coast (Canada) as well. Or at least, that's my best guess so far.
Cache is probably a good guess. I don't do infinite scrolls but I do use Reddit mostly for hobby subreddits which aren't as popular and less likely to be in cache.
I imagine it probably has some to do with specific geography as well. Cloudflare will proxy back to nearest node and maybe some are better than others.
You'd get timeouts, and I'd never see them - despite being West Coast (Canada) as well. Or at least, that's my best guess so far.