I last blogged about Pokemon Go more than two and a half years ago (almost a year after its initial release of July 2016), and I've gone from a measly 60 caught to a whopping 355 caught, including a complete Kanto Pokedex (the first 151 Pokemon). At that time I'd enjoyed the game and appreciated its cultural impact, but the game itself wasn't all that memorable to me. However, over time developer Niantic gradually rolled out more and more features, and now the game has a robust set of options and modes that definitely make it feel like a more complete experience.
The Wikipedia article on the game has a good run-down of all the features and when they were added. Among them the feature that wins my vote for best update was the Adventure Sync feature. Previously you had to have the app open for it to track your steps, or the pricey Pokemon Go Plus accessory. The Adventure Sync feature keeps track of your steps even when the app is closed, which makes hatching eggs and earning candies from your Pokemon buddy way easier.
I hadn't played the game much before the addition of raid battles, but they definitely have become a big draw for a lot of people. Raid battles are a way that groups can get together to take down powerful (often legendary) Pokemon. I was happy to ignore them for the most part, but I finally had to resort to getting involved with them in order to finally complete my Kanto Pokedex, which required me to battle Mewtwo in a raid. It was a tense affair, and I had to travel to two Pokestops and cross my fingers as you not only have to beat the Pokemon, but throw special raid-specific Pokeballs to catch it. Luck was on my side and I was able to catch it on my second raid, and that hour of raid experience was definitely enough for me, although, again, I can appreciate the social aspects of raids and if I had friends who were really into it I probably wouldn't mind tagging along. Raid battles have proven to be popular enough that they've even made it into the latest proper Pokemon game, so I suppose I'll be encountering them again before too long.
One of two other newer features worth mentioning are the "research" tasks, which consist of a series of quests or missions such as "Make 10 Great throws" that earn your items and in multi-part missions, special Pokemon. This helps give the game more of a purpose and was a worthwhile diversion in general. The other was the introduction of "Community Days", which is where a certain Pokemon is highlighted and appears frequently for a few hours on a weekend. That Pokemon learns a special move when it evolves during that time, and its shiny variant also becomes much more common. I didn't get into these events much and I'm not a shiny hunter in general, but I did catch a couple of shinies this way, which was a nice, cheap thrill, haha.
From my perspective Niantic's updates within the last year have been pretty ho-hum, but this would be understandable since the game continues to rake in the cash and they've probably been busy developing and releasing their Harry Potter game which has similar mechanics. I have so many mobile games to keep track of in general that once I finished my Kanto Pokedex I put Pokemon Go aside for now, but as of right now it doesn't seem to show any signs of slowing down, so it will be interesting to see how the game continues to evolve.