JamesNK also answered this. We started off with just nuget packages, it was beautiful for about 5 minutes until we ended up with ~300 in the default project. Then physics kicked in, slower build times, slower compilation times, slower intellisense. All of those old O(N/N^2) algorithms started to show up on profiles and we had to do something about it. That was just the practical performance side of things, then there was the customer confusion around which packages had which APIs. We offered a .NET buffet that customers hated. On top of that, the versioning got nuts. Each of those packages could in theory version independently, who is going to test all of those combinations of things? What happens when you need tot publish ~300 + packages to your server deployment because you didn't want to "install the framework"? You'd be complaining that they were too many assemblies (which people did). Amplify that by deploying these binaries to the same physical machine when running multiple .NET Core applications there (very popular for IIS setups). We pre-JIT (ready to run) the core libraries and ASP.NET to improve startup time, that makes the assemblies bigger (as they contain both native code and IL), this makes your applications bigger by default.

We got LOTS of feedback that this was all really terrible and we listened.

We did this from .NET Core's inception to .NET Core 3.0 when we pulled the plug. We set things up so that the base install/platform/framework was not composed of packages but framework references. We merged several assemblies together to get rid of some of the unnecessary layering. We invented shared frameworks so that people could install the framework once and run lots of applications using shared libraries so that:

- Customers have faster publish times as you only need to deploy your application bits, the framework can be pre-installed - Loading the same dll on disk into multiple processes allows for more virtual memory sharing (a handy performance optimization) - We could version the set (.NET, ASP.NET Core) as a coherent unit - We could pre-JIT (R2R) the built in stuff so it's installed on the machine once and usable by many apps.

As for being intuitive, the default experience is to use the Web SDK. I didn't even get into SDKs but it does more than default the framework reference. It also exposes capabilities that tooling use to light up behaviors in the build and in the IDE.

PS: This stuff is harder than it looks on the surface and we spend lots of time and take lots of care designing it (making the typical tradeoffs you make when doing software engineering).