Say you're making a chat app - you wouldn't incorporate a delete feature, and you might be tempted to use some kind of blockchain to prove all messages were delivered without gaps. But if you ignore archival needs you design something similar to IRC which is much simpler.
Reproducibility adds nothing here
Not that you are wrong, industry keeps thinking they can make themselves immune and so long term reproducibility is useful, but I submit they are wrong.
Literally none of your statements are applicable to that realm, sorry.
Rail operators have long since been operating their air-gapped infrastructure with 99.999% safety results, literally not adhering to any of the policies you claim are endemic to the industry.
Toolchains absolutely need to be maintained with some degree of longevity.
The whole world doesn’t march to your consumer-user beat. Sometimes it functions at industrial-user tempo’s, too ..
