Whether the algorithms seem effective to you, as a single consumer of the advertisements, is irrelevant.
Facebook ad campaigns most definitely work (though I'd imagine there's some variance of effectiveness based on what exactly you're trying to sell with the ad campaigns), and lookalike audiences are an effective way of determining who to show your ads to.
It's really quite simple, as a company you can spend money on Facebook ads and you will get traffic/conversions/etc.
Facebook ad campaigns most definitely work (though I'd imagine there's some variance of effectiveness based on what exactly you're trying to sell with the ad campaigns), and lookalike audiences are an effective way of determining who to show your ads to.
It's really quite simple, as a company you can spend money on Facebook ads and you will get traffic/conversions/etc.