Yes, there are marketing budgets, and spending money to guarantee a long-form video that will be a seen by a good audience for your game is a great investment.
BUT
That means you'd NEVER spend money on what you could get for free.
But not YouTubers. The vast majority of us work for free. Send us review code, and if the game's good, free video.
Which brings us to the odd scenario - why would you offer to pay a YouTuber FIRST, before just offering them code?
Receiving such an email about any game always makes me a little more lukewarm about it.