It's only after you get down into the technical weeds - and they are admittedly rather weedy - that it becomes clear that this is much harder than it seems and not something we're going to be able to solve.
The people working in my field also are quite skeptical of our ability to do this. It ultimately boils down to the problem of building complex systems that are reliable and that work, and that problem has long predated the problem of access to encryption keys.
What encryption lets us do is say, "Yes, the Internet is insecure." Bad guys are able to compromise computers everywhere, but we're able to tolerate that because if they do intercept our messages, they can't do any harm with it.
As the local police department might want to decrypt a phone of a criminal suspect, so would the Chinese or the Russian or the Iranian intelligence agencies like to be able to do exactly the same thing.
In order for any smartphone manufacturer to decrypt the data on your phone, it has to hold onto a secret that lets it get that access. And that secret or that database of secrets becomes an extremely valuable and useful target for intelligence agencies.
If it were possible to hold onto this sort of database and really be assured that only good guys get access to it, we might have a different discussion. Unfortunately, we don't know how to build systems that work that way. We don't know how to do this without creating a big target and a big vulnerability.