How are people thinking about shared carts across search, video, email, and retail sites?

Quick note before the question. I am not an affiliate marketer for any brand mentioned here.

I have been thinking about the Universal Cart announcement and whether it is more than a shopping feature.

If people can add products from search, video, email, AI tools, and retailer sites into one cart, that could change where the buying decision happens.

The question is not only which retailer wins.

The bigger question is where the shopper makes the final choice.

If the cart appears earlier in the buying process, a store may become one option within a larger buying flow.

That raises a few questions.

Does this affect large marketplaces first, or smaller retailers first?

Do ads become less about earning the click and more about being present at the point of purchase?

How does this change retail media and search monetization?

Curious how others read this.

Is a shared cart mostly about convenience, or is it a sign that more of the buying process is moving outside retailer websites?