If you don't have a good phone and a high speed connection, you don't have any money to spend on either the sites products or the products of their advertisers.
When looked at from that angle, bloat is a feature.
It's not reasonable to have an expectation of quality when it comes to the web.
Well that take sure goes from 0 to 60 real fast. Can you really be sure that only people with good phones and connections have money to spend? Just to poke some obvious holes: what about old rich people who have a distaste for modern phones but spend lavishly on vacations every year? Or outdoorsy rich people who are frequently in areas with poor cell coverage but are constantly purchasing expensive camping/climbing equipment? How about people who aren’t rich, but work for companies where their input is part of a purchasing process with millions of dollars of budget? Those people are all super-lucrative advertising targets, I don’t think advertisers are intentionally weeding them out.
But I doubt companies purposely increase their hosting costs as some kind of firewall to only include the rich. More like they just don’t care. Same reason for technical debt, everyone wants to grow and move needles.
If a company could magically make their site more available and efficient for free I am sure they would jump at the chance. But spending a million on that vs. a million on ads wont seem worth it.
This is addressed in TFA and is not true. The bloat is a symptom of what I've seen referred to as the "laptop class" and is unrelated to any feature adjacent.
When looked at from that angle, bloat is a feature.
It's not reasonable to have an expectation of quality when it comes to the web.