https://imgur.com/a/QAT5BiV https://imgur.com/a/QAT5BiV Above is profilers of the 2 apps. There's a MASSIVE amount of JS that has to start and run. Note 1.2s

https://imgur.com/a/QAT5BiV https://imgur.com/a/QAT5BiV Above is profilers of the 2 apps. There's a MASSIVE amount of JS that has to start and run. Note 1.2s of scripting for full load on old, with 4.6s of scripting on new. Rendering also triples in size because they're using a lot more CSS. Note also that the "rich" sidebars in themselves have an extremely long load time and pop in. They do this because they made bad technological decisions, and took an off the shelf low-content SPA-style framework to make what is mostly a static site. Its also quite likely that they haven't done much tuning. They probably were tasked with making widgets and new features over anything having to do with performance, and especially the ad delivery network.