Why didnt Goku alter time when he met Young Roshi?

[GurixDr34]

In the original Dragon Ball Show Goku travels back in time and meets a Young Roshi i wonder how this didnt affect the timeline like it did with Future Trunks i dont know if this story also happens in the Manga

[BernardoCairo]

It's filler. Toei introduced it before Toriyama came up with the idea of time travelling and how that would work. Just ignore the whole if it bothers you. Same goes for that weird origin they gave to the Dragon Balls in the beginning of the show.

[MasenkoHA]

There's a lot of discrepancies. Like Crane Hermit didn't become evil until after Piccolo Daimao's first reign of terror but the past in that episode already shows him to be evil. Roshi is shown as a pervert even at 18 years old, but that doesn't make sense because he was once able to ride the Kinto-un, suggesting he didn't become a sexual deviant until centuries of being a hermit and sexual repression. Mutaito also appears to be stronger than Goku but that can't be true because Mutaito had to use the Mafuba to defeat Piccolo.

The best handwave is Mr.Popo didn't actually send Goku back in time but to an illusion of the past. Roshi and Crane have the personalities they developed as old men because that's how Goku recognizes them. Mutaito is stronger than Goku in this fake past so Goku would be willing to listen and learn about chi control. Since Goku didn't go back to the actual past, the timeline was unchanged.

[Hellspawn28]

Out of Universe Answer: Filler

In Universe Answer: Mr. Popo's time travel isn't the same as we see from Bluma's time machine. It is more of an illusion than the actual past.

[theherodjl]

Kami's temple has a few odd rooms in which time & space is seemingly traversed, ranging from the Earth/Planet Vegeta in the distant past or whatever quasi-afterlife-dimension it is that the previous Kami reside in. And yet, the people who 'travel' away in one of these rooms always end up back at the temple, as though they had never actually left like Yajirobe once stated. So I imagine Kami's temple isn't so much an actual gateway to other places across the universe/timeline, but more of a magical simulation generator that approximates other places across the universe/timeline, not unlike the holodeck from Star Trek. It would explain the discrepancies of how Mutaito was somehow stronger than Goku and why Roshi & Shen were already acting similar to how they are in the present, as well as the fact as to why it's never brought up again. It's just simulated conjecture.
You can't alter the events of reality if it's not actually real.