"I come" is not a natural English sentence. "I return" or "I arrive" are more appropriate given the translations provided
It's not meant to be a natural sentence. It's simply showing you how to use the verb 'datang' using pronouns. The verbs for 'to return' and 'to arrive' are not the same as 'to come' so they wouldn't be appropriate translations.
Will i offend myself if i use the wrong one? Haha jk. Very unique that there is a formal/informal distinction in the first person. Is it like, "your humble servant" ?