Pop music simply doesn't generally use such techniques, as explained. A pop artist who was well educated musically and wanted to use modulation could certainly use it, however if there was more than a very moderate amount, it would no longer be pop, but some form of "art music".
Do pop songs have key changes?
Key changes are given a hard time by music purists over the years, mainly thanks to X Factor winner's singles and the like. But we reckon they are an underrated and powerful tool for any classic pop (or even rock) tune, and some of the finest songs ever have contained a cheeky key change or two.
What does pop music use?
Identifying factors usually include repeated choruses and hooks, short to medium-length songs written in a basic format (often the verse-chorus structure), and rhythms or tempos that can be easily danced to. Much pop music also borrows elements from other styles such as rock, urban, dance, Latin, and country.
Why does pop music sound so bad?
Music loudness has been manipulated by the use of compression. Compression boosts the volume of the quietest parts of the song so they match the loudest parts, reducing dynamic range. With everything now loud, it gives music a muddled sound, as everything has less punch and vibrancy due to compression.