Hello,
There are some many different functions from many different libraries to import SAS, SPSS, Excel, etc. data into R converting the datasets into dataframes.
However, using RStudio and the "Import Dataset" menu, we can do that without learning/using any of those functions...Is that correct?
Why would we use any of those functions at all when RStudio does it so easily for us?
The RStudio IDE is only providing integration features (a GUI) for some packages (e.g. haven, readr, readxl, etc), it doesn't implement the functionality on its own. Since R is open source with a lot of contributors, some of them have different ideas on how to implement any given functionality (like reading data from files) so they create their own packages with slightly different functionalities, syntax, and general approaches to the task.
You might encounter a situation where a specific file is not being read into memory the way you need or want and another package is more suitable for that specific case.