The internet will be around, it just won't be open anymore.

Already the trolls,etc were a nuicance enough that anonymous social-media,etc is starting to become outlawed. Sure people will hack,etc but the easy exploitation of today will be a fleeting thing once we patch the fundamentally broken stuff.

Remember how Windows machines were wormed in the early 00s? MS got their act together and today the primary target is via browsers or Excel-files,etc. The recent Linux RCE while bad and probably not alone, is still not the common case.