they are different in styles because they are different people Yes, they are

That does not answer these discrepancies:

Contemporary historians and biblical scholars tend to treat the canonical Gospels as works produced in specific first‑century Christian contexts rather than straightforward eyewitness memoirs: many scholars judge the Gospels anonymous, composed in Greek for communities across the Roman Empire, with Mark likely written first and serving as a source for Matthew and Luke (the Synoptic Problem), while John’s Gospel is notably different in style and theology.

They were written miles and years apart from each other.