So why not use one of the myriad launchers (such as Nexus) that make it much easier?
1 read each mod description, recent comments and bugs
2 install it exactly as described
3 always test, start the game teleport around
4 repeat
The issue is mods can conflict, and this conflicts cause crashes and most of the time there is no clue who is at fault, debugging crashes is very time consuming, try to Google "Skyrim CTD" you will see how many hours, energy and peace was lost because of this.
This new Collection feature is an attempt to automate some of this steps, it is an improvement but is not the correct solution.
It also does not solve the issue where some old mod has a bug but is illegal for me to publish a fixed version, at most I might be able to create a patch then create a list of instructions on how to get the original mod and patch it.
The point is that the users likely don't want to only add one addon, but several. It's not permissable to create addon packs as a compilation of a known working combination. Nexus does have something that lets you install multiple add-ons like a package manager but few exists, because it doesn't work well enough if adjustments are necessary
Or maybe those users just think you’re wrong?
AFAIK most people use a package manager to install multiple mods and it works just fine in most cases.
In my opinion being able to install mods individually is much preferable to mod packs since you don’t have to add a bunch of stuff you don’t want and don’t have to wait for the pack compiler to update all the individual mods etc.
There are many concepts, plugins, scripts, load order, meshes, textures, ENB, patches, SKSE .dll files, SKSE loader and the address library, version issues etc.
Maybe you never tried Minecraft modded, it is easy for new people to get started and you still have all the options for installing mods one by one.