If you automatically update your dependencies all the time, you will constantly get new bugs, issues and sometimes even malware. If you don't update your dependencies all the time, you will be vulnerable to old bugs and issues. The current software engineering paradigm has no meaningful answer to this , no matter what "security experts" tell you. In a sane industry this realization would lead to a change of the parad…
You could formally spec software and implement it, congrats you're now 1000x slower to market and any change you want to make is another 1000x investment to spec out and prove.
And let's not even mention the ridiculous idea that open source developers be expected to do this. Moreover, this doesn't even handle hardware problems!
Okay, but we could just build all the software internally, reinvent all the wheels. But how is this any better? Now you have even less manpower to fix bugs and you're probably 100x slower to market because you're building all these half baked, bug ridden libraries.
If anything, the best idea is formally verified sandboxing, so that you have strong assurances about certain apps not doing bad stuff, but this doesn't solve all problems either.
It's an unsolvable problem in general, which is why no one has solved it.