Oh is that why mobile design seems to have taken over so much! I keep running into sites with uselessly gigantic fonts and big square buttons, and I assumed it

Oh is that why mobile design seems to have taken over so much! I keep running into sites with uselessly gigantic fonts and big square buttons, and I assumed it was either laziness and an assumption that everyone is browsing on a phone, or just another inexplicable designer fad. Do people really just not use portrait-mode windows?