If companies are serious about their products, the founder should always be the one to market them.
It starts there and everything else is downstream of that.
Example: Google launched their latest Pixel smartphone this week.
Nothing against Trevor Noah, host of the event, but the strategy of using third party celebrities and influencers to launch products is wrong.
Google have spent billions on pushing Pixel smartphones for decades via ads, influencers etc and yet have 1% market share. 1%!
Founders bring something no amount of marketing dollars spent elsewhere can.
You can bet your last dollar that if Jobs were alive he'd be the one presenting every Apple Launch event still.
Likewise there's no way Elon would let some VP or rando unveil the upcoming Tesla Roadster.
This applies to any business regardless of scale or size, even solo founders.
If it doesn't come from the founder, it's probably nothing.