I feel like most phones nowadays don't really care about a 5mb difference considering they have multiple GB's of space. At least on my phone, the space taken by the actual app binaries is negligible compared to media.
One app being 5MB larger is negligible. 50 apps being 5MB larger isn't a huge problem but it is significant. Modern phones have gigabytes of storage but not many gigabytes.
I also didn't see that the difference is just 5MB. Most apps are in the double or even triple digits.
In addition, caring about anything being 3 times larger than necessary stikes me as the right mindset. Individual items may insignificant but they add up. It's certainly better than the electron-ic opposite.
Most people have no concept of how much space things take. When their phone fills up because of too many videos of toddlers bumbling around they assume it's the apps.