Witches, like the one Saul hired, normally deal with demons posing as spirit this or spirit that. Same with mediums etc if they are more than mere hucksters. Does that make them real or not? Actually, it is immaterial. They are condemned not for their power but for their spiritual perversion and corruption.
More to the point, man is not an inconcquential creature spiritually even if we are presently in harms way unless we repent and we, as a race, have been filling up this world with our curses for thousands of years. This has to have an effect. The “spells” they say they use may be meaningless whereby witches are being further decieved but behind them lay the misuseand abuse of what tatters of authority Mankind still retains.
Oh, the spirits of the infernal are real, and may be summoned in the lack of the welcome of Jesus.
Many people hate Jesus in various ways. We’ve viewed two of those ways (at least) on this very thread.