One can argue that, if one doesn't look too closely how that "limiting of each other" tends to work in practice, and how it tends to work out in the end.
We have many, many examples of presidential republics, where both a president and a parliament have equal constitutional claim to represent the will of the people.
We see them reel from one constitutional crisis to another like a drunken sailor.
The US has fared comparatively well, as presidential republics go - so far. I don't know why, maybe because some groups have been more willing to yield to preserve the prestige of the institution as a whole. Given that it's the most prestigious presidential republic by a mile, that wouldn't be so surprising.
But it makes sense then, that this subservience will eventually get pushed further and further, until everything breaks.
It's no coincidence that most of the countries that at some point become more autocratic are presidential republics.
Linz has argued that presidential republics have the following issues:
- dual democracy legitimacy (both president and legislature claim popular mandate)
- rigidity (fixed term rather than parliamentary approval prevents adaptation to crises)
- winner take all logic (total exclusion of opposition from power)
- personalization of power (authority concentration)
Further, the Carnegie Endowment in 2025 found that autocratic transitions occur at "striking speed" in presidential systems.
[1] https://kellogg.nd.edu/sites/default/files/old_files/documen...