If websites implement this, it will effectively make building a web search engine impossible for new entrants. The current players can whitelist/attest their own clients while categorizing every other scraping clients as bots.
If not for other reasons, I can't see how Google a search company can be allowed to push something that can kill competition using its market dominance in other areas like browsers.
Because antitrust has been dead for a while. Chrome is a tool to drive people to Google and Google ads and nothing more.
I will say, I did appreciate Microsoft having a browser engine with IE and Edge, even if the former was notoriously a pain, it gave competition in the space. Unfortunately, that's not the case anymore and everything is either Chrome (Blink), Firefox (Gecko), or Safari (WebKit). And it's pretty clear what Chrome has done once that have amassed a dominant market share.
I'm sure there are Googlers who think they're legitimately making the web a safer place, but I think the real reason is pretty clear if you take a birds eye view.
My mother's new Windows 11 laptop's out-of-the-box configuration had me clicking through half a dozen things attempting to manipulate me or her into spending more money. There are (I can only assume paid-placement) news and adfotainment in the start menu! Repeat pop-up reminders from Lenovo to subscribe to their protection package. Emotionally-manipulative reminders to subscribe to virus protection services. To Microsoft Office. Etc. etc.
It's been the same thing in the mobile market, where the move to "apps" means you are running their software on your device all the time, so they can optimally surveil you, and target the advertisements and behaviourally-modifying nudges. Quite a few messaging services now actively mess with delivery of notifications, spacing them out, delaying them, according to research that shows what maximizes engagement.
I saw the trend 20 years ago and switched to free software around that time -- I liked Linux anyway, but it was partly on principle. Still, the new laptop was eye-opening. The degree of intrusion, the degree to which even desktop computers have turned into user-hostile advertising terminals serving the purposes of their manufacturer, rather than a computer for the user to accomplish their work, is quite shocking.
Everything networked is becoming like that - twisting the user's hardware, turning it into nothing more than a terminal, an extension of the corporation, serving their interests at all times. Even smart TVs now have ads built-in to their menus and such.