People need to stop saying Riolu is similar to Greninja or Infernape, Frogadier evolved in the second year of XY and previous, the rest of Ash's Pokémon has lots of battles, especially Talonflame. Ash got Chimchar at the end of the first year of DP and while it had lots of focus as a Chimchar, it only evolved into Infernape at the last year of DP.
Considering Infernape's overall win count in all forms, I would disagree because I clearly recall people hating on it for that(not that I cared, I enjoyed it), especially during the battle with Candice and of course the league match with Paul, going so far as to label it as worse than Charizard.
Greninja also did go there once the Ash-Greninja transformation plot kicked in as they focused on that more than the rest of his team.
It hasn't been even a year for Journeys and Riolu gets so much focus and will continue to get unless Ash gets a bigger shillmon and the rest gets barely anything, they are Palpitoad tier at this point because even the weakest Ash's Pokémon like Torkoal still had some screentime.
if Screentime alone was enough to give the "ace" status to a pokemon Totodile would've been Ash's jouto ace simply due to how much it was used compared to the others, but in the end it never had any good battle feats to it's name other than beating Sneasal in the league, and that's pretty sad all things considered.
It matters more to me what a pokemon does combat wise than what it does screentime wise, because just seeing it a lot doesn't mean it's going to be a strong fighter.
Even then if Riolu does turn out to be Ash's "Ace" I wouldn't have a problem with it given how popular it is overall and the fact that I do like it, I mean if it was a pokemon that you liked you'd probably look the other way yourself and not be hating it.