If BTC becomes the predominant world currency / reserve currency / etc, how will we trust computer manufacturers and OS developers?

And even if the manufacturers don't do anything nefarious themselves, who is to say that EVERYONE that handles the hardware across the supply chains can be trusted or OS developers? Is the trend towards a completely open source OS? But that only seems to take care of the software side of things.

What I'm saying is... BTC is the most secure network in the world, but that doesn't mean that there won't be more and more advanced ways for people to try to steal it from you. In fact, I think it's the opposite. Thieves will become more and more advanced.

How will us everyday common man know that our computers are safe?

And before someone says hardware wallets, how do we know those are safe?

All it takes is 1 guy in a lot of instances, right?

Imagine that 1.0 BTC is worth $20 million per BTC in today's terms... you're going to tell me everyone that handles the supply chain for computers / hardware / OSes doesn't have incentive to install a backdoor or something shady?

I dunno... seems like the biggest potential attack vector in the future, imo.