Mobile webapps are usually terrible. There are many reasons why mobile websites are given low priority by companies – the main one being they want you to download their app. Apps are more likely to be used often, have access to far more device sensors/location than webpages, allowing for greater demographic targeting. Nowadays, there are two main platforms to cover 90%+ of the population, so a universal webapp is not as much as necessity. In addition, adblockers on web browsers are ubiquitous, but not many people know how to block ads within apps.
“Unfortunately, this isn’t the case for most mobile sites. After the first render, content is changed and moved around. New content is added not just at the end but also right in the middle. The most common examples are images, videos, menus, sidebars, interactive widgets and advertisement banners. Also custom fonts affect the overall layout.”