I remember the day they introduced the chronological newsfeed! People were pissed about that. Nobody wanted a list of all their wall posts to be published to everyone who could see them.

Prior to newsfeed, FB was obviously an N-N platform, but the interactions were more 1-1. You used the network to find and connect, but you interacted with individuals (on their wall). The newsfeed tipped the focus toward 1-N interactions, and direct messages solidified that (no more wall posts).

I believe GP is comparing pre-feed and post-feed days, not chrono feed vs algo feed.

For its first few years, Facebook had no feed at all.

You are correct, but the introduction of the algorithm is indeed just as if not as significant as the introduction of the feed