The best part about this cycle is that developers can always point to some metric which shows improvement to justify their actions, resulting in an Escher-like loop where they think they’re always going up.
These cycles pop up all the time in development as priorities shift (or as developers find more excuses to “fix” what isn’t broken). Real world coding always involves compromise - leadership is recognizing which compromises to make without continually backpedaling.
To be fair, small fast messenger 2020 is "better" (aka more features / millisecond of cold start) than small fast messenger 2016. The cycle doesn't always go up monotonically, even if developers pretend it does. But it is possible to go "full-circle" through the loop and wind up in a better place than you started, and it's even possible for each stage of the loop to be truly justified given product needs.
indeed, it could be rational business needs. at a time when it's more expensive to hire devs, maybe it looks better to have a single codebase. at a time when performance is more valued, maybe it's better to rewrite in native.
I don't know what world you live in, but in my world developers don't have to look for excuses to do work. Perhaps some companies running on endless VC overhire, but the real working world has fewer employees for most positions than it needs.
And in the case of Messenger, I highly doubt it was the developers who said, "Hey, let's add this completely unrelated thing to our codebase - payments!". More likely it was marketing or "product" that told the devs what to add.
These cycles pop up all the time in development as priorities shift (or as developers find more excuses to “fix” what isn’t broken). Real world coding always involves compromise - leadership is recognizing which compromises to make without continually backpedaling.