I completely agree that people getting fired from their jobs is not the same as getting shot in Soviet Union.
On the other hand, you are minimising the problem here. Getting "cancelled" is just one possible consequence of the... let's call it Twitter PC Mob Culture. Other frequent consequence is people getting fired from their jobs -- and that can easily happen to a burger flipper or Uber driver.
Both are essentially the same thing: attacking someone's livelihood as a revenge for expressing an unorthodox opinion. It's just, if someone's sole source of income is their paycheck, you get them fired; and if they also make some extra money by giving lectures, you also get those lectures cancelled. Sure, if you only focus on the part about cancelling lectures, then yes, that part only happens to those who give lectures, of course.
How high are the stake of losing one's job? Depends; some people find a new job easier than others. If something like that happened to me now, it would be quite inconvenient. But suppose I would be lucky and find a new job overnight; would it mean that getting me fired was no big deal?
If we talk about individual victims, of course we are likely to mention the famous ones. If I tried to name a cancer victim other people know, I would probably say Steve Jobs -- not because he is a typical cancer victim, but because he is a cancer victim I expect other people to know about. Also, him being famous is precisely why I know about this fact. So, if we try to discuss victims of Twitter PC Mob Culture, of course someone like Eric Weinstein is very likely to be mentioned. But that doesn't mean that the threat is limited to people like Eric Weinstein. It just means that if the same thing happens to me tomorrow, you will probably never hear about it.