Agreed! There are many things in IT industry that are prone to this kind of almost magical thinking, and "boundaries" / "tight coupling" is one of them. I realized that when tried to actually compare some stuff I had been doing at work through years, being fascinated with uncoupling things. Well, if you start measuring it, even at the top level (time, people, money spent) then it is so clear that there are obvious tight couplings at architecture level (like data on wire containing some structure or transferring a state of application), and it is very tempting to remove them. But then we may actually find ourselves having a subtle tight coupling, totally not obvious, but effecting in a need of two teams or even two tech stacks and a budget more than twice the size because of communication / coordination costs.