When he falls headlong eventually he can make no use of the wealth he has hoarded and which has caused him to imagine himself in no need of Allah or His guidance. His wealth will not avail him when he falls headlong. Facilitating evil and sin is the same as facilitating the way to affliction, even though the sinful person may be successful and prosperous in this life. Indeed, Hell is affliction itself. Thus the first part of the surah ends having made clear that there are only two ways for all mankind in all times and places.
All humanity is in two parties under two headings however numerous are their colours and forms.
The second part states the fate of each group. I warn you, therefore. Preserved from it will be the righteous, who gives away his money to purify himself, not in recompense of any favour done him by anyone. He simply seeks the pleasure of His Lord, the Most High. He shall indeed be well content.