I am not sure how usefull that information would actually be.

You can visit the Steam page for their download data worldwide. They have a nice chart that has glow points on a global map. 

https://store.steampowered.com/stats/content/ 

you need to click on satellite view. This at least tells you where many people live that have gaming computers.

While itch infrastructure is somewhat translated, game pages are not. So you can assume that most customers here understand enough internet english to cope.

Let us look at movies. On the US market. Would they prefer foreign movies spoken in English? Probably. But how does the reality look like? Foreign movies are released with subtitles. Why so? Because there is no big localization industry. Why should there? Hollywood produces in English ready to go. They use actual actors to voice animation. Now switch to non-english countries. There usually is some kind of business sector that specializes in translating and voicing foreign stuff, including English. Those can be so good that they surpass mediocre originals, so the localized version is actually better in quality. And they use not actors that speak, but voice actors.

What I am trying to say, rather complicated and wordy: it depends.

How good will the translation be. How good will the voice acting be? Also, this is games, is the voiceover needed at all for the game play? Is it important? Will the game be better with it, more accessible?

In the early days of video games, voice was horrible, as they did not use voice actors. As budgets grew, games got voiced same as animation movies.

So, what are you talking about? AI voice overs, translated by AI as well? Maybe go with subbing. I somehow doubt you are talking about professional voicing in separate languages for an indie game. Not even AAA games do that very often.

As for the languages themselves, it should be the same distribution as native speakers. Adjusted for the markets you plan to release to. You can also look at some popular games, if and what languages they are localized to, and why.

Some of my games are translated into Russian (and localised for language, there's no other localisation relevant). Some of my games are translated into Spanish.

 None of my translated games are more popular than the games only available in English. 

On my own website, as opposed to itch.io, my top visitors are from USA, Russia and South Africa (where I live). The remaining countries are where Huawei cell phones are popular, because Huawei organically promotes my browser games better than any other store. From that list there isn't a stand-out country. I haven't ticked the block for China on the Huawei store else it would definitely be a stand-out country (because I don't understand their copyright requirements).

With the Russian I don't know which came first - the audience or the translation. I did authenticate my website through Yandex (top Russian search engine). Yandex 's computer gave me more useful tips (in English) on my website than the other search engines' computers (this was years ago). I also listed my website on Duckduckgo.com and they were partnering with Yandex at first (I don't think they still are). Some of my views on itch.io come from Yandex.

But the translations are incidental - I happened to meet translators elsewhere and they translated my games as a barter agreement for editing help or we made the games together.

The other sites say Spanish, French and German are popular languages because the people will pay for games and not everyone speaks English. But I did find they will try a game anyway. I try to show how to play the game in a video so they don't need text, and use symbols inside the game. When I was publishing on Google I put the instructions on how to play as part of the description so if they were Google translating the page, they would see how to play. But that was only the case when I was promoting the game externally (free for a day). Else I don't think they'd even notice the game.