"They don't advertise or demonstrate how recent PCs are thousand times better than old ones. They still offer PCs with crap configurations such as no SSD or only 2 GB of RAM of retardedly bad screens."
1000 is a big number. Perhaps if you still are on a 386 you would be right.
My new cheap laptop is a bit faster than my 7 years old one, but it cost peanuts and has no fan.
For performance you star paying with fan noise, battery time, weight and so on.
Same for desktop PCs. My old gaming PC is not far off a new one in performance per Watt, and I don't want to have a massive electricity bill, so won't be upgrading any time soon.