There's plenty of moddable games still available though. Factorio, Stardew Valley, Minecraft, Beat Saber. Even Dota 2 has what they call "custom games".

Sure, maybe not a golden age, but they're doing alright

The mods for modern games involve making those games better for a specific audience. I've played a bunch of Stardew Valley and Minecraft mods. High-end Minecraft graphics and massive content packs make for an interesting (if buggy) experience.

On the other hand, it's completely different from the Use Map Settings games I grew up playing in Brood War, which were radically different games using Starcraft assets. DotA was literally the same thing in WC3. The game became a game engine. There's nothing like that now. (Garry's Mod?)

Roblox, I think, though it's targeted to kids and I don't know much about it.

Roblox is a scam. The biggest games in the world like csgo still allow and cekebrate modding, itself originally being a halflife mod.

In what way is Roblox a scam? Remember that most people here know very little about it.

1) It's full of pay-to-win / pay-to-play / work-to-play / work-to-not-get-paid modded servers

2) Roblox Corp does all it can to obfuscate this from parents/guardians and maintain the predatory system to benefit from a cut.

I wish any of those hit the levels that Warcraft 3 did. Having infinite, sophisticated game modes to play online with others was so fun. Unfortunately Fortnite, Roblox, and Dota 2 have not been able to do this nearly as well.

Minecraft most assuredly has done this.

It's basically just a game engine now.

I remember playing the brainy tekkit modpacks (which tend to have 300+ mods inside) that add a whole bunch of new mechanics to the game to the point where you're designing each piece of a factory and trying to put it together to automate resource collection. Then after a week once you finally have all the pieces created, and fuel refined, you can launch off in a rocket to the moon and beyond.

I remember playing the competitive UHC (ultra hardcore) servers. These were the inspiration for pubg/fortnight. Once you die, you're out, last-man-standing wins. 350 players would be randomly dispersed in a 10x10km world. And after 1 hour the world border would shrink in 1km every 10 minutes. If you were outside the border you would be teleported to a random space inside the playzone. What do you do to win? Create alliances? Head for the center to try and build fortifications to get the drop on players who are teleported near the center? Collect resources to build the best weapons and defences to fight people coming in with the ever shifting border? Sneak around to backstab a player and steal their resources? etc... etc... (Badlion UHC was my server of choice, there's some great youtube videos out there)

I remember playing in the casual fun mario-party style minigame servers.

I remember try to survive in the hardcore survival modpacks like the one where you're in a plane that's crashed in the desert next to an abandoned city, and you have to very carefully manage your heat/water while trying to scratch enough to survive while being assaulted by extremely difficult enemies.

I remember playing the nostalgia filled pixelcraft (literally just pokemon in minecraft).

I remember playing the challenging skyblock. This is where you're on a tiny island with a single tree floating in an infinite void, and you need to very carefully use your resources to expand your island to create your own world.

I remember the enhancement mods that just added new features to the game (biomes, creatures, dimensions, technology, magic, etc...)

I remember playing the adventure maps that creators would upload. These are worlds that are essentially read-only, and you're only allowed to interact with what the creator lets you. Essentially an adventure game like Legend of Zelda or Tomb Raider.

I remember just playing the base game with friends.

There's so much to love in minecraft and its mods expand the game so much further.

The people that would have made mods for those games are still able to make mods for TES, Witcher, GTA, Stardew valley (off the top of my head), but the people who made full blown mods like DOTA in WC3 are now using tools like Unity or js frameworks like pixi and publishing on itch.io instead.

It's a shame that some studios are extremely against modding. Take for example Riot Games, I love their games but no modding support at all for League of Legends or Valorant. Considering their competition (Dota2 and CS:GO respectively) have an active community of producers and consumers of custom game content (maps, skins, game modes, etc), it's a real disappointment. I know leadership must believe the benefit isn't worth the cost, but a small part of me believes it's because the studio doesn't want to be "shown up" by the community getting excited about content they didn't make. I'm reminded of the Replay system in League of Legends. The community requested it for many years and was always told it wasn't going to happen, but once a third party releases a web app that allows you to download your previous games, suddenly the studio allocates a huge effort into getting an official version out the door.

I don't think so. Steam, for example, supports mods directly from the Steam client. Many of the games I play specifically support mods from within the game itself, integrated with this Steam mod functionality, and it even takes care of upgrades, dependencies and such.

There's a thriving ecosystem of games and mods out there, no such thing as a golden age that has ended.

Starcraft II for example has a host of excellent mods. My group doesn't even play the original Starcraft game, and I don't have any interest in it either, but we have sunk many hours into different custom maps.

Lotta good mods (addons) for WoW these days! I’m particularly enamored with TellMeWhen