Personally I am finding it increasingly difficult to read the Post without noticing bias. I would encourage comparing this article to Klobuchar's own description of the bill before coming to your own conclusion. https://www.klobuchar.senate.gov/public/index.cfm/2021/2/sen...
It would seem the portion of the bill in question regards, "exclusionary conduct". Like if Amazon refused to list retailers that compete with its own Amazon Basics brand, akin to a grocery store refusing to sell Rice Crispies because it competes with their own Crisp Ricies. Not necessarily precluding them from offering the products.
Even then that's only a small bullet point in a much larger bill. Most of the intent seems to be focused on increasing the capacity and resources for pursuing cases pertaining to anti-competitive mergers and acquisitions by these companies. The potential for exclusionary conduct becomes particularly concerning given the current trend of a few corporations gobbling up everything in their path that even remotely competes with their products.
Thing is it doesn't matter if a product is a good idea which solves a niche problem if it's involved with these massive companies. If that product doesn't make a billion dollars then it finds itself in the Google Graveyard. Personally I don't want to see new and innovative things have a bad deal forced upon them, only to merge into a morass of vanilla ice cream because they didn't make ALL the money.