There's a big difference between being sponsored by the very product you are reviewing in this specific video, and being sponsored by something unrelated while being openly and obviously presented as sponsored content.
I don't see what's the problem. It's a proposal of a sponsorship with payment in nature (the expensive phones) instead of money. If the influencer disagrees, there's no problem and they can buy the phones by themselves, Google is not forced by law to send free phones to influencers.
I don't think that all those influencers are actually playing raid shadow legends or eating factor or using betterhelp.
Google is giving free review samples to real reviewers
The first problem is that Google is giving an incentive to influencers - who are supposed to be (more or less) impartia - to review their phone favourably compared to alternatives.
The second problem is that, despite being one of the biggest companies in the world, they did this in the most obvious way possible. Now who will trust any positive review of their phone? Anyone with common sense, let alone the lawyers whom I suppose cleared this - should have told them not to do something so dumb.
Edit: corrected reviewers to influencers, for the reasons explained below.
There are YouTube channels/instagrammers that exclusively review sponsored products. Bigger ones like Unbox therapy, LTT shortcircuit, and so on. Never a bad word about the shitty product they're reviewing, because it's a paid ad.
Take a look by yourself. The product they're "reviewing" is clearly non functioning e-waste, yet they don't say it to make the advertiser happy.
This is a program dedicated to influencers, not reviewers. The verge, Engadget, marques, Mr mobile, they didn't sign this contract. If Google believes that the outlet is legit, they give the review device for free without the sponsorship contract.
Edit for clarity as I didn't add a paragraph between this sentence:
When the influencer that got the free phone under this ad campaign shows the phone on camera they need to flag the post with #giftfromgoogle and #teampixel - you can use that as a hint that the review is biased
Advertisements should be explicit. You'll often see sponsored segments of videos when a YouTuber is talking about a product, where they explicitly say it's sponsored. These influences are being asked to treat the product preferential to other devices without being a sponsor.
Advertising is one thing. Asking people to advertise your product without revealing that it's an ad is something else.