In San Francisco Bay Area, it's been a three pack for quite a while... followed by a "More places" link and then by organic results.
Depending on the query, the organic results return a mixture of individual companies/establishments and UGC local directories like Yelp and TripAdvisor, along with some price comparison sites that also offer user reviews.
The nature of the listings also varies by query and the nature of where users might be. This is from my desktop that's located across the bay from SF...
...for "pizza" in San Francisco (with the city name specified), two of the three sites in the 3-pack are Zagat-rated, and only of them has a website, but it's not linked from the 3-pack. Geo-distribution shown on the map skews towards popular trendy neighborhoods. Yelp is on top of the mixed organic results, one of which is the website for one of the 3-pack places.
...for "lawyers" in SF, on the other hand, the geo-distribution is in the downtown area (as I've come to expect for this niche), all of the companies have websites that are linked to in the 3-pack, and the directories include FindLaw, SF Bar Association, plus Yelp, etc.
Without the cityname specified, results become highly localized as determined by my location.
Maps included in all of above. Worth noting that with some one-word queries like "pizza", where the query is both an entity and a food... with no location specified, Google is returning both a map up top and a Knowledge Graph panel with pizza nutritional information (in the right column up at the top). For "bread", in the 3-pack, Google returns well-known artisan bakeries in the area, so there is a commitment of sorts to local establishments with reputations in the 3-pack.