Depending on the percentages provided in the contract, voice talent could be taking millions out of games
The residual they're asking for is not a percentage. It's a fee of $3300 when the units sold passes the thresholds of 2 million, 4 million, 6 million and 8 million copies sold. You're overestimating the impact of the VO payments imo.
I was curious about how the math shook out so I did some number crunching.
Let's say there are 30 VOs on a AAA project and your game hits 2 million copies sold. That's a $99,000 payment total to the 30 actors. Let's say your game makes it all the way to 8 million copies sold (congrats!). All four bonus payments to the actor pool totals $396,000 ($13,200 per actor). Keep in mind those payments will likely be split many months or even years apart unless you're a rare AAA game.
Let's say every game unit nets 20 dollars; that's $160 million in revenue. Your team has 150 people and it took you 4 years to develop your AAA game. Let's say your devs make $20/hr or $58,400/year each. That's $8,760,000 to pay your main staff per year or $35,040,000 for the entire 4 years. You have about $125 million left... maybe we'll pay out original VO costs and marketing - assuming they are not in-house - and whatever else so let's say there's $100 million dollars of profit after all that. That all goes to the developer. Take away $396,000 to VO residuals because you sold 8 million copies and that leaves you with the paltry sum of $99,604,000 for the publisher and optionally to inflate the salaries of the devs in the equation as you see fit.
Even if they're netting $10/unit, that's $80 mil in revenue at 8 million copies sold and $45 million leftover after paying your dev team, heck let's throw in a 10 million dollar buffer zone for marketing and original VO costs ($35 mill now), leaving you with $34,604,000 for publishers and additional devs/upping dev salaries after your four payments to the VO team.
According to this article, publishers net about $16/unit so the truth is probably somewhere in between those examples (if you squint and tilt your head).