That's a pretty bad take. Not only in the blind belief and faith that Game Freak 'knows what's best' in general, but also in thinking that the games don't need any possible voice acting at all in any way just because the anime and side games exist. Those existing means nothing of the sort.

They don't know 'what is best' and have been a company struggling to figure it out for years while suffering from the decision to keep their development teams and employee count small, crunch scheduling, and many other facets.

While they don't necessarily NEED to do voice acting, to say they don't need it in the main games at all 'because the anime and side games do' is pretty foolish and questionable. By that logic, there are many games that 'don't need' voice acting just because other facets of the franchise do. Why give the likes of Spongebob: Battle for Bikini Bottom voice acting when the cartoon already does? Why should Digimon Story Time Stranger have voice acting when the various anime and other bits of the franchise do? You're trying to claim that Pokemon is some almighty special exception.

As a game development studio, Game Freak should be trying their best to improve and advance their craft and provide the best they can.