That is not an option if you are a profit driven enterprise. There is no alternative that is as good/optimized as Google Ads is. You are literally bidding on search intent.
Evidence says otherwise. Hard data shows that conversions happen the most through these advertising networks. Can't deny the obvious. Unless you want us all to go back to the pre-Internet era where we cold called clients and vendors with a hope of getting leads. We have technology for a reason. Not all tech is bad. Not all advertising is bad either. It is the intent that matters.
Information search. The last time you looked up how to do something, for example, you bought a product off of a Google ad?
What do you define as a "conversion?" I specifically said "sales." People in the ad biz want to define "conversion" as something else- but those of us paying for the ads want to make a sale. If somebody (or a bot) who has no intention of buying clicks on the ad it's a mistake for both of us. Yet with Google anyway, any attempt I make to keep people from mis-clicking (by putting a price in the ad, for example, to indicate up front that if you're looking for free this is not your link) earns me a penalty by reducing something deceptively labeled as my "quality score."
I would love to see the numbers you are referring to, though. Maybe something would occur to me to help me see how to navigate the mess.
Oh, that's too easy: Something that indicates the person is willing to make a purchase. My guess is you do searched all day long, and if you saw ads (you probably block them) you wouldn't buy much.
Where do you go when you want to buy something? Google? Probably not. That's why Amazon is dominating. Google can be used for branding, I'm told, and that's important- but requires a different mindset.