Thats mostly because of the overload quantity of ads, trackers, plugins, integrations, etc all websites have now. Using an adblocker halves your bandwidth usage. If you have a data cap, an adblocker is a must.

And then, optimization. As an Angular developer, knowing many websites nowadays are Angular or similar, the lack of optimization is a big problem. Most don't even use lazy loading, not to mention managing the module imports into different components. They import everything into the main component and don't do lazy loading leading you to websites that have 20-40MB (!!!) of initial load (when you open the website). This is so common that I think junior angular devs will slowly just kill angular popularity and give it a bad look. Takes work to optimize Angular, and many devs don't care enough and just rush it. And then there are companies that don't understand that web frameworks need optimization and just underpay devs or rush the dev time.

Please don't use Angular (or similar complex web frameworks like Vue or React) if you don't know how to correctly optimize it, or don't have time or care for it. And don't overload your pages with ads and integrations. You are ruining the web.