This is really scary for all journalists who wants to express their themselves on various issues involving the rich and powerful in the society.
it's not actually confirmed that was the real reason why he was killed/murdered/disappeared (or even
exactly what happened to him). Of course, it's not an unreasonable supposition to think it, but there is no genuine evidence.
I say this in particular because Kashoggi had a colorful family background; he was nephew to the famous Saudi arms dealer Adnan Kashoggi. Adnan Kashoggi has an extraordinary reputation and life story, he was selling weapons into the 1980's Iraq/Iran war, as well as the contras in Guatemala (or was it Nicaragua?). He was ridiculously wealthy, was well known for parties that lasted 3-4 days at his luxurious properties, in places like Spain and the USA. In other words, Uncle Adnan had some really strong political friends in US and Europe, which of course he needed to be an arms dealer in wars that US and European powers were involved in.
So was Jamal Kashoggi
just an innocent Saudi journalist, fighting the House of Sa'ud for the Saudi people? Maybe, but growing up with an Uncle like Adnan, he could easily have been doing another job (or 3) at the same time, using the journalist role as cover (which also gave anyone he annoyed the cover they needed to kill him). Without any proper evidence, it's difficult to say anything for certain.