This is a pretty common model for countries which became independent of the UK; Ireland did more or less the same copy-paste job, but in the 1920s, so ended up with a _way_ weaker president than in the US model (the Irish presidency is more or less a standin for a constitutional monarch, with ~no real powers) and upper house, and stronger lower house.

Authoritarian US is becoming the reality right now and the first amendment provides exactly zero protection. We are watching US constitution collapse right now.

Second, its meaning IS obscure. It get reinterpreted and modified by supreme court to unrecognizable degree. The words dont mean what they used to mean back then, because court used some alternative history to achieve their political goal. It is also not like the court was grounded in contemporary reality when making those decisions and explaining them.

Most of constitutional protections are weak. There is no recourse if your rights are broken, only ever increasing maze of special conditions and requirements you need to fill if you want those protections to apply.