It sounds like what you're arguing for is that companies ought to have employees that are irreplaceable. Wouldn't that impose a huge risk to the company? If said employee gets hit by the proverbial bus or leaves, the company should just fold?
Companies need to build systems where everyone is replaceable to de-risk the business and not because they don't get programmers.
But they ( companies ) don't. Looking back at my career, what you do get is, various ranges of alignment to an idea ( whatever it may be ). Some companies do it better than others. Usually, the smaller the company, the easier it is for the owner/founder/main guy to make sure his vision is appropriately enforced, but that gets so much harder in bigger ones so the systems they generate get progressively less sensible. And yes, I don't think search for absolutely replaceable employees shows any kind of faith in one's company. It does, however, show an interesting frame of mind that I personally like to avoid.
For all the talk about innovation, you don't get that by making everyone an interchangeable cog. You want at least some people, who are difficult to be replaced, because they are your competitive edge ( I am saying difficult, because I personally also do not believe anyone is truly irreplaceable ).
And again, the risk to a company, especially a tech company, is falling behind. Losing an employee is a fact of life type of risk; effectively unavoidable. Still, that kind of fake modularity is wrong, not because modularity is a bad idea ( it is not ), but because companies absolutely fucking suck at designing that kind of a system ( as evidenced by reality itself ).
All this is before we get to some of the more human aspect of all this ( up until now we were talking about companies as if they are a living thing with wills and what not and an amalgamation of humans, where one action is a function of thousands little decisions ) like: people messing with systems in a way that does the exact opposite of what the company 'wants'.
All in all, it is an interesting argument, and I even agree with it at some level, but I do not think it survives closer inspection.
If a company doesn't have irreplaceable people, then that company is not doing anything interesting. Conversely, if replaceable people can produce your (software) product, then any other company can also do it.
As much as I don't like LLMs that much personally, do you think ChatGPT was produced with replaceable people?
> Companies need to build systems where everyone is replaceable...
No they don't. They need to build systems where everyone is happy with their job and don't need to constantly hop jobs for better salary, environment, etc.
The way to mitigate the bus factor is not to make everybody replaceable; it is to have a process to develop more irreplaceable people with overlapping expertise in their areas.