your computers are much less secure in general but they also have different security assumptions

phones are the pinnacle of security in this point in time. rooting them not only breaks but also breaks the security assumptions that apps rely on

for example I can be sure that no other app has access in my data as an app dev. based on that assumption i might store secrets. which on android/iOS is totally fine (there are better ways but ok)

you’d never make such an assumption on a pc app. you’d find another way. there’s no such thing as “my data” on desktop. hence you develop around it