> Where is inheritance?

It's been widely considered as a mistake for about two decades now...

> I couldn't even find a standard linked list.

Even? If you need a linked list, then you have a 0.01% use case and shouldn't expect such a niche data structure to be easily available. That said, https://pkg.go.dev/container/list

> What if I have a list where I need to make lots of insertions in the middle?

Then you should use an array. If you're not making full use of the pointer-y nature of a linked list, you shouldn't be using it.

> Where is the data structures package?

Go only got generics in 2022 so the standard library is lacking in ergonomic data structures.