You can thank google and facebook. Google has total control with chrome browsing being used for the majority of web browsers. So much so that web devs are being told it is best practice to code their websites specifically optimized for chrome. They also implemented tracking from everything to page position to mouse position to pages / words / links clicked. Then it saves what font color size position of the things you interacted with. Facebook created the react programing language which is the most commonly used language for dynamic web pages. For non tech people think that the website has to constantly be in connection with the database in order to dynamically chance elements (things you interact with) in real time (notice things change before you submit anything). They also have their own spy software as well as other NSA companies like social media integration which also have their spy software. Back then you only used HTML and CSS, very light and easily processed languages because most computers did not have the processing power or memory that we do today due to the declining cost of CPU's and RAM. Combine that with the fact that people consider themselves software "engineers" without understanding any big O or memory constraints. Most computers can run 2ghz and have 4gb ram. People submit garbage bloated code because the industry no longer cares about quality but only how quickly you can get a shit product online. Usually the CEO of the week is paid in stock options based on how quickly they can get a product online and creating revenue. All they want to do is get their options before the product breaks, sell and upgrade to the next job leaving the next manager with an unstable, broken nightmare.