A design choice usually made by companies that involves making the front-end UI overly simple and very modernized. It tends to involve adding rounded corners and removing detail, alongside other modern design aspects. This can be seen in Google Chrome, Microsoft Windows, and many other user interfaces designed by big companies.
Reasoning
The reasoning behind this phenomenon is relative. One reason is that when web 2 was beginning and the internet was becoming more mainstream, companies wanted their logos to feel natural and more inviting, not digital, so they added 3D effects to their logos (e.g. the reflection on the pre-2011 YouTube logo.). Once most people became used to the internet and it became more mainstream, they started making their logos more modern and simple. This results in oversimplification.
Another reason is that companies wanted their logo to stand out in advertisements, and also while the internet was becoming mainstream, logos were important to establish a website and make it memorable. Now for widespread companies, their logos usually are already known and don't need to be displayed as much on websites, resulting in the removal of detail from their logos.