Buildings have strict construction codes, and this improves the overall quality of buildings. If developing software is to be more like other professions, it should strive to move in this direction
As many other regulations, construction codes are there, because otherwise unrelated people lose property, get injured or even die. A building may deprive neighbors from enough sunlight, and that is unhealthy, so there are standards for insolation. A badly done electrical wiring can overload or short circuit - and the fire doesn't know about property ownership and jumps onto the neighborhood.
In a imaginary scenario, if one's on their own land, with no one else around (and no woods to burn, no basins to pollute, etc etc) - I don't think mandatory state building codes would make any sense. And in the virtual space, things are frequently just like that - if something goes kaboom, it only impacts that system. Of course, some exceptions apply (NTP DDoS amplifiers, misconfigured MTAs or hacked websites abused for spam, etc).
And I think IM apps are very different from housing. Usually, compromised communications do not have any impact on third parties. And when they do there are usually provisions for that, e.g. HIPAA.
And its users. Unless you're the one living in the house (in which case I agree, do whatever you want) there has to be a certain guaranteed safety so the roof doesn't fall down on its tenants. I don't want to be a civil engineering expert to choose the place where I live; I expect the plumbing to work and the electricity to be safe. Likewise, a software user shouldn't have to be an expert in order to get safe software.
Most commercial software products aren't pieces of art, they are pieces of engineering like cars and bridges, and should behave as such
(Of course, there is software that is more akin to pieces of art; videogames come to mind. Even then, they shouldn't compromise the privacy of unsuspecting users)
Users are part of that system. If the system in centralized - it's a bus, not a car - if it crashes, everyone get injured. (BTW, should EP mandate distributed architecture or 6-nines SLAs? Reliability is as important as confidentiality.) The real problem is not that communications aren't encrypted or something. It's that users aren't aware what they get and what they don't.
> I don't want to be a civil engineering expert
Neither do I. But regarding software - I don't need to be an expert to hear "we can't access your messages even if we would want to". Why need government for that? And why make it mandatory? I just don't see your point except for analogies with other professions. What's the point of programming being like car manufacturing?
Personally, I want to be informed but free to chose whatever fits my requirements. That doesn't work well for buildings and cars (for the reasons I've mentioned in the parent comment), but that works very well for software. Non-mandatory certifications and attestations works just fine - e.g. we have IM software audited.
Interventions may be necessary if no one builds E2E messengers (assuming there is a demand - and there is), or all existing software is unusable. But I don't think the communications software market is that unhealthy.
And as I've said before, if someone advertises something as e.g. "100% secure" or "we can't read your messages" but it's false - that's basically a misadvertising.