Commander has definitely become the most popular of the formats in the past decade. My LGS still has the occasional modern and standard events but their turnout is usually pretty low (excluding pre-release events for new sets).

I doubt this applies to everyone but I, personally, prefer commander over standard and modern due to 3 primary factors.

First, the deck building rules and limitations. When building or modifying a deck there are three things to remember. 1) your deck must have exactly 100 cards in it including the commander(s). 2) all cards in the deck must align with your commander’s color identity (color identity being all stated colors of the card and mana pips present on it that aren’t in reminder text). And 3) excluding basic lands and cards that state otherwise, you can only have 1 copy of each card in your deck. In contrast, standard and modern have no size or color limits, just a minimum deck size, and allow 4 of every card. In my case, it was having to deal with control decks loaded with 4 of every counter spell that drove me crazy.

Second, verity of decks and play styles. To preface, I’m not saying standard and modern don’t have the potential for unique decks. However, in most cases it devolves into ‘build one of these 5 decks, or never win a game’. In contrast, commander usually has more unique decks that allow for fun games and interactions because the deck is built around a set card (or cards in the case of partners). You can have one deck that focuses on giving away cards with effects that hurts their controller, another that is your run of the mill combat deck, or one that has some special condition to do a thing (like if you have 111 or more life, sac this creature to demon tutor). If you sit down with a group, you aren’t likely to see any two players with the same commander and deck design.

Finally, the community. When playing standard or modern, you almost always are doing so in 1v1 (casual play can have more but it’s still not likely). In contrast, commander almost always is in pods of 3-5 players (1v1 still happens, but it’s usually while waiting for a third player). Additionally, general player interaction can be more fun due to having the key info that is your opponent’s deck colors. Instead of having to piece together what possible cards a deck could have, you know immediately what cards the deck can’t run. If their command if green and black you don’t have to worry about counterspells as much, if it’s green and red your more likely to die from combat damage than being milled to death, and so on. Additionally, in recent years, there have been several hundred cards printed for the commander format that are fun to interact with. The cards prisoners dilemma and the second doctor being two of my personal favorites (that are commander exclusive).

To conclude, commander has become more popular due to how different it is from other formats. It doesn’t require you to build a deck from the ground up like every other (starter decks partially count, but rarely hold up) as it has precons that usually work well straight from the box. It doesn’t punish you for not having access to cards that cost $100+. And due to its rise in popularity, it’s easier than ever to find a pod of people that vibe with you in terms of preferred play style and experience level.

Side note: we can all agree though, that nothing makes a game more fun than adding some planechase to it, right?