I think the problem is that most people are used to ready-made products. Even I, who have nothing to do with digital technologies and programming, read the instructions and when I fully understood what to do I moved on. Also for any questions the grin forum is hyperactive and ready to answer from simple questions to complex for anyone who is really interested. I don’t think the problem is focused on Grin. Also with an easy to use wallet (I do not mention for obvious reasons) for exchange your cryptos you will do what you want really fast but with very high fees. After some time most people understand that it is not worth it!
Even slatepack is a simple “copy-paste” and the transaction takes place in a very short time. I don’t think it’s that difficult or abstruse.
I don’t understand how you mean “easily”.
For those who do not mine Grin, there are platforms and exchanges. Some are good and some are not. In the forum there are descriptions and experiences and according to them we can choose what suits us. I do not believe that Grin or its developers are responsible for the way some exchanges work also.