DY: Pashtus is that that Mishnah/concept is not Aliba D’R’ Yaakov, who holds of Schar Mitzvos B’hai Alma Leika.
I believe I once saw a Maharsha (I think in Kesubos) who actually asks and answers your question, though. He thinks everything on that list are those Mitzvos that inherently and actively (unclear what the fine line is between these and all other Mitzvos) make you a better person. Therefore, the Peiros that you get from them in Olam HaZeh is just more Mitzvos. It’s not any Schar. All Schar is in Olam Haba. These have Peiros in this world because they have direct effects on this world that will come into play in everyday life (better relationships with parents/neighbors, doing more Mitzvos, etc.).
I have to think about whether holding Schar Mitzvos B’hai Alma Leika means that there can still be Onesh in this world. I find it highly unlikely, but I’ll look into it B”N.