sure but what you’re effectively doing is making an employer hire more people than otherwise so they can have adequate cover. you may say this just the cost of doing business. But in the aggregate it results in X percent of companies that were previously neutral or making a profit into going out of business or being in the negative.
They need to have this anyway because they never know what might happen to that person. They could say tomorrow they have another job, or as my old boss used to say "got hit by a bus" and died. You'd have no recourse then, so you better have redundancy.
Of course, every job I've ever been in has been terrible about redundancy, and when people start leaving, usually it's the people with the most domain knowledge, and so you get a big gut punch right away, and then it snowballs as more work and responsibilities get put on other people and they end up leaving once they've had enough or found something better, and it just keeps increasing until you're basically totally screwed but hey, you're saving money by not having to pay all these employees anymore, and that's all your stockholders are going to see for the first year until your company completely falls apart.
No, you still need MORE redundancy. If 10 units is enough redundancy to deal with a failure rate of X, if X now increases then you will need more than 10 units for redundancy. The reasons don't matter at all. More chance of failure means more redundancy required.
I was being sarcastic near the end. That seems to be what the higher ups think. I definitely think there needs to be lots of redundancy, as someone who has been the recipient of a bunch of dumped on extra responsibility with little knowledge transfer as people have left.