Uninstall bbPress: Please follow this
Log into your WordPress back-end.
Go to Plugins > Installed Plugins.
Scroll down until you see bbPress and click Deactivate.
After the page reloads, scroll back down to the bbPress plugin, now click the red Delete link.
You will now see a screen to confirm your deletion of the bbPress plugin, if you are sure you want to remove bbPress from your installation, hit the OK. button.
bbPress is now uninstalled from your site.
I know how to delete it
What I don’t know, why after I deleted it there was still writing like the one in the image above?
bbpress leaves this behind for reasons I won’t bore you with.
Without bbpress, the role has nothing it can do, so you can just leave it.
If you want to get rid of it (and I can understand if you do) then it is just a wordpress role, so see
How to Delete User Roles from a WordPress Site
What do you mean: “I won’t bore you with”?
I mean that there are reasons why the role is left, but they are too tedious for me to make the effort to explain them, and you would be bored reading them 🙂
So will that role slow down my web loading? Because I don’t like any unused data that is still stored because it can slow down loading
you can delete it with no problems, but then fact that the role exists will not slow your site downloading, as it is only when you access the backend user that this parameter is accessed in the database.
for clarity the reasons it is left are to do with reinstalling bbpress, which since you have deleted means you can delete the role
I didn’t reinstall bbpress, and when I deleted the role it wasn’t deleted? Why? Did it leave the database table?