You are absolutely right. I worked at a big agency where I managed a team that ran the search ads for a fortune 500 tech company. That was usually how it worked. I tried to communicate up the chain that the dinners and outings on Google's dime are a clear conflict of interest, but nobody wanted to hear it.

By far the most dissapointing thing was that the client often just wanted to go with Google's recomendations or they had even worse ideas. Even when we really tried to look out for the best interests of the client it was like fighting an uphill battle both ways.

Another problem is that anything that isn't direct response is hard to measure so it's tough to make a clear and compelling case. Anybody can chalk up any hare brained idea to brand value and it is tough to push back on that when the client doesn't really care.

Like, everyone in the industry shows agency reps a good time. Back a decade ago, FB reps used to get the clients drunk the night before they'd see Google on the principle that they'd remember less.

However it's worth pointing out that Google as an org have absolutely hated ad agencies for many years, in fact being nice to the agencies was a strategy used by FB when I was there.

I'm not disputing your point about optimisations, but the notion that Google like ad agencies is just ludicrous.