Until recently I was using a Oneplus X with 16GB storage just fine. I was never tempted to download apps except the ones I completely needed (because I really didn't have room for it.)

Now, with a Pixel 4a the System/OS singlehandedly uses 18GB of storage. Today, I do not see myself ever filling up another 100GB of apps but who knows what app sizes will look like in 5 more years.