It's pretty surprising how seemingly no Minecraft YouTubers talk about the downfall of the Minecraft modding community, so I'll leave a little rant about it here.
Back in the day, when Minecraft was officially still in Beta, modding was rather crude and full of pitfalls. The modding API you would use would be Risugami's ModLoader. To install ModLoader itself, you would have to open up minecraft.jar, add and replace files in it, and then delete META-INF to start off. A lot of mods could be installed by simply dropping the .jar files into a designated folder, but a lot of mods would also need to replace .class files in minecraft.jar, and eventually you would end up with conflicts and incompatibilities. And if you didn't install mods one by one, while making backups of minecraft.jar at every step, you would have to reinstall everything if some mod added to minecraft.jar caused the game to crash.
All of this changed somewhere around the official release of Minecraft 1.0, when a new modding API, Forge, was created. It was a reverse engineer project based off of Risugami's ModLoader, therefore mods made for ModLoader would work on Forge. The biggest advantage of Forge was the fact that you no longer had to dig into minecraft.jar, the entirety of the mod could be place in a separate .jar file in the mods folder, and if a mod caused problems all it took was the removal of this single file.
Forge would get updates every new Minecraft version, and so would the mods for it. Throughout the history of the updates, certain versions would get longer support from the modding community, such as version 1.7.10 or version 1.12.2. However around the time 1.12.2 was released and 1.13 was on it's way, many people were disappointed with Forge's slow updates and bad performance, which led to the creation of a new modding API, Fabric. This unfortunately led to the downfall of the modding community, as everyone would get divided over this new reality.
First, let's start with the fact that there are now two modding API's, which are completely incompatible with each other. Mods made for Forge can't be loaded through Fabric and vice versa. And you cannot use both API's on a single instance because of how radically different they go about modding the game. So now, many modders have declared that they will make mods for Forge only and won't adapt to the new API that is Fabric, others have declared that they will make mods for Fabric only and won't support the legacy API that is Forge, and some simply made their mods for both API's so that no one is left out.
The other issue that arose is the version division. Many modders have refused to update their mods to versions beyond 1.12.2, which could be explained with the fact that they would either have to choose one API or make their mods for two separate API's at once, which is well over what they're willing to do for the mod. The other part of the modders have declared that the future is now and that 1.12.2 doesn't deserve any more attention, so their mods are being made for the newest versions only and they won't get backported to 1.12.2, which was a common practice back in the day for very popular mods. Many modpacks have stayed on 1.12.2 such as the famous RLCraft due to this divison.
All of this has caused the modding community to get completely fragmented, and most importantly, the community hasn't established a new "long term support" version as they did with 1.7.10 or 1.12.2. I believe the main issue here is the API division. People cannot agree on which API is the best choice, so they sure as hell won't agree on a single version to continue to support for a longer time. Instead mods keep drifting between the newest versions and stagnating on older versions, which leads to the fact that modpacks don't really get updated to the newest versions anymore due to how many mods stay behind.
The modding community as it is right now is on the brink of extinction if no singular agreement will be made. Back in the day, it was simple. First you had a single API, Risugami's ModLoader which was the backbone of all the mods, then you had Minecraft Forge which was fully backwards compatible with ModLoader. And for years the one option you had was Forge, and it worked well, until the disagreements with the Forge project and the creation of Fabric, a completely different, incompatible API, which now coexists with Forge. And it doesn't seem to change anytime soon unless the impossible happens and both API's end up being cross-compatible.
