I've always felt that backgrounds were one of the strongest additions to 5e, but that they never were capitalized upon fully. It is such a rich way to individuate a bog-standard fighter (for example), through a single player choice. And instantly they become more interesting, and easier to role-play. It was genius.
There are many ways that they could have gone with them over the years. During the initial playtest, I hoped that rather than having extra starting skills, the distinctive part of rogues was that they had two backgrounds: the Entertainer Acolyte, the Gladiator Sage, the Charlatan Noble. That would give them the extra skills and tools by default, but it would also give them a story that was operationalized through things on the character sheet.
In addition, there was the feature -- something you got from the background that couldn't be got elsewhere. Some of them were pretty lame, but some were fun and cool. The hermit had a Secret that you worked up with your DM. The Noble could have three plot-resistant NPCs following you around; a sailor could have a bad reputation. It was always something to lean into in roleplaying, and could be fun. The Charlatan's ability to forge documents, stated as fact, as well as a fully established secret identity was in many was the golden apple of all of these.
Did the player base all take advantage of this? No; but they didn't need to. There was a richness there for those that wanted it, and something you could sometimes trot out to make the game more interesting.
For me, the biggest loss of the new backgrounds is the loss of these features. I liked the tables outlining the basic motivations -- really helpful for new and younger players, I felt. The new backgrounds are now instead just a bundle-of-mechanical-abilities, including several (languages, ASI) that do not seem to fit comfortably.
Compare the Guide (playtest) with the Outlander (PHB). The outlander's feature says they can scramble up food and water for a party of 5. Cool and fun. Guide feels pale and limited (especially since it presents the presumption that you speak giant and are a primal spellcaster). That, to me, feels really regressive.
To be clear: I don't think it's all bad.
The addition of more working-class backgrounds is needed. Artisan, Farmer, Laborer, Pilgrim are all rich additions, to reflect that adventurers can come from the masses, as it should be. (Folk Hero was the closest in the PHB, but even that I felt constraining. One of my custom character backgrounds was Shepherd, which I was always proud of.
I want to think more about languages. The addition of Sign Language is great; The inclusion of Druidic and Thieves' Cant is significant, and even though it makes it non-exclusive for rogues and druids, it could lead to more use in game, which is a win.
