I must say that @Wasmachineman_NL does have a valid point here.
Android apps are designed with portrait orientation in mind, and while all (that I use) support landscape somehow, most do not even try to make any clever use of a wide screen. There are a few notable exceptions (like K9-Mail) but they are rare.
When using Lineage, I rarely slide out the keyboard for that simple reason: For many on-the-go tasks -- like single-handed web browsing, email checking, or even writing short messages -- landscape is not practical, as, both, the apps and the (huge) phone are simply not optimised