Are paid ads for big players only?

I recently talked with a friend who is a self-proclaimed expert on online marketing.
He claims that small e-shops should stay away from paid ads (fb and google) as it is a losing game for them, almost impossible to get decent Roas or even break-even (only possible for big shops with lots of sales an data).

How true is it? Is organic the only or best way to go for starting e-commerces?