The WSJ is a large site that gets lots of traffic. I assume they have a competent web team, which knows that long load times on mobile suck and knows how to do performance optimization to some degree. I am willing to bet that whatever low-hanging fruit there was to improve their PLT has already been plucked, and the remaining slowness is the complicated stuff I mentioned earlier.

That's why I think statements like your original comment are unhelpfully reductionist, and my paraphrasing of them was not misleading.