Ok, I went and counted. The collar landing page has 611 divs for a banner, a text block and six products, and the same thing built with core blocks on a test install came out at a bit over 200, and I cant argue that away, that is just junk in the page. You're right on that.
So for a new client shop I'd try blocks first. We have one coming in November (a small bike parts shop, two people, they want to edit their own promo pages) and I'd rather build them synced patterns like Natalia did than hand them another Elementor licence, and if the owner cant work with it after a week we still have the old way.
Where I don't move: the existing Elementor shops stay. The dog harness owner has 40 landing pages she built herself over three years and a rebuild would cost her more than the 300 ms earns her, and she'd have to relearn everything (she still calls the sidebar "the thingy on the left"). That would be me solving my problem, not hers.