I think you're being downvoted since you are rhetorically asking questions people have already beat to death. The main two answers being (a) each virus behaves

I think you're being downvoted since you are rhetorically asking questions people have already beat to death. The main two answers being (a) each virus behaves differently, so extrapolation should be done carefully, and not just from your personal experience with surviving past flu's (b) there isn't a limit on how much vaccine we can produce in total, so there isn't really a good reason not to get it. That's perhaps like saying the flu vaccine is only half effective (which is true), so I'd rather get sick twice as often, rather than signal that I trust science.