I mean I think in terms of maintainer resources Linux is one of the projects with the least to worry about, there are always companies who are willing to have a team work on stuff.
Those megacorps also accumulate endless complexity internally, as does the industry as a whole. It's a problem larger than the discipline of reviewers of C code could ever hope to fix.
Basically on our current trajectory we will end up with something like the biosphere that can do stuff but too complex to fully understand --- but also probably well more fragile than that?
Even the larger world outside the field is somewhat aware of the the looming complexity problem: https://www.theatlantic.com/technology/archive/2017/09/savin...
Basically on our current trajectory we will end up with something like the biosphere that can do stuff but too complex to fully understand --- but also probably well more fragile than that?