Technology

So websites are all made with these frameworks for three reasons. The first one is, it's suppose to save an server cost. If a server can send parts of code and data at a time, it should be faster. Unfortunately bad web architects do not benchmarks these things. More server calls means more headers for the same amount of data. Web developers, for several reasons sometimes out of their control, do not handle errors properly like in the Chinese e-commerce site you mentioned. So yes, you are correct, it does suck and some pages would be better off as a flat page.

The second reason is culture. AJAX first started in the 90s when users were still on 56k modems. We needed pages to load faster or else the user thought it was dead or just too annoying to stay. So this became the culture. We are no longer mimicking paper, we are creating web apps, or programs. This stays with the culture now. I've seen single page websites do it where I actually think it's detrimental.

The third reason user experience. This is in two parts which can be consider the same. The first is it's not a familiar site, users want the app experience on a website or else they leave. The second which is the nearly same is if the page does not refresh, you keep the attention of the user for a lot longer. It's like reading a really good book but there are no page turns or chapters. In social media, this is support important. eCommerce, adding items without a refresh is really important or else they might change their mind.

As for profits for users of a website, the algorithm should be something like this:

if( profitsFromOldDevices > (developmentTime+resources) ) 
    startDevelopment();

Most of the time, this is false. Designers and developers and project managers take up a lot of money. People on really old devices are less likely to buy things. eCommerce sites know this, and advertisers know this.

When I say older devices, I meant over 2 decades old. The latest Firefox can still be installed in Android 5, which came out over a decade ago.

As for e-waste, I am not an expert on that but seeing how much electricity a Pentium 3 desktop can take, a $200 dollar smart phone can save the person money very quickly.

As for Apple, they are greenwashers but they probably have the best recycling program out of all the top hardware manufacturers. I'm sure companies like the Fairphone are leagues better though.

As for YouTube, I'm going to guess it's going run decently if you have a fairly recent browser. If you have Javascript turned off, Google can't get much info off the user. So this is their way of forcing updating.

You don't need to apologize about ranting. Have you seen how long my post? This is your post. Do as you wish. Have fun.