I've set up an extension that randomized my user agent string, to see what would happen, and some major sites were severely broken. Some gave me degraded mode (

I've set up an extension that randomized my user agent string, to see what would happen, and some major sites were severely broken. Some gave me degraded mode (google did that several times). Also many sites use user agent for things like OS detection, so if you want correct downloads, must have at least partially correct UA. One can argue that yes, in 2018, there should be APIs that allow to detect all this stuff in a much better way than parsing random mess of legacy markers that is a common user agent. But in reality, parsing UA string is still the case and unfortunately keeps being the case, including very major and technically advanced sites.