Yes. Ideally a codebase is just a monorepo of pure functions and apps are simply the control flow that weaves them. Write reusable libraries not microservices (silos).
Sadly incentives are not aligned for this at scale - easier to buy cloud SaaS n+1 whose sales team insist "this $badware solves a Hard Problem" while your devs sit in ceremonies all day.
That's why Paul Graham started Y Combinator and handed the entrepreneurial reins to the developers instead of the project managers and MBAs and made billions in the process.
maybe that was true once, as I understand it current YC is just a finishing school for t1 grads to pad the CV between graduation and working as a "thought leader" (lol)
Sadly incentives are not aligned for this at scale - easier to buy cloud SaaS n+1 whose sales team insist "this $badware solves a Hard Problem" while your devs sit in ceremonies all day.