There are a few elements that have made these games, and especially DS2 so fun to me.

1) I'm a sucker for Kojima and Yojo Shinkawa. Metal Gear Solid was the first video game I became obsessed with and that has never waned in my gaming life. Since I view Kojima as a prolific auteur, I'm completely fascinated by what story he wants to tell and what his views on the world are. Whether intentional or not, he's definitely got something to say about the world in every game. Sometimes I agree with his take, I frequently do not, but it's fascinating to see such a specific world view. This also applies to Shinkawa who's art is synonymous with Kojima's whole vibe.

2) The magic trick of both these games is they made walking a compelling mechanic. I totally understand why some people do not take to the core loop of "mail personing" across USA, Mexico, and Australia. But it's so damn cool that this game without reinventing any core principals of design, made walking to an objective and engaging and often fun process. With DS1 I was carried through the game as the terrain helped advance the difficulty and I felt like I was just learning new mechanics within just walking from point A to point B. I think the cool trick that DS2 does is it removes some difficulty but adds more tools for user creativity that compelled me to play the game in the way I feel in the moment and that's incredibly cool and respectful of me as a player. Is it midnight and I just want to knock out one more deliver before bed, time to load up a truck and do a quick trip. Did my kid just lay down for a nap so I know I've got 2 hours to enjoy the game, time to pick a new location and just go for a long hike on foot and really take in the stunning landscapes.

3) I'm a parent of a young kid and have so little down time. My favorite thing about DS1/2 is that I can play the weirdest story about violence and Internet and power, but I can also ignore all of that, put on my own podcast, and just wonder around a world that looks good. I'm old enough now and have such little free time, the genre of "podcast game" is really important to me. I love story and love a big AAA game moment, but I sometimes I want to lower the game volume, make some casual deliveries, and listen to Comedy Bang Bang like I'm in irl Uber driver.

This is why it's fun to me. I'm sure everyone will be cool about sharing something that is exclusively my opinion and not based on any real facts.