> It's simply not as clear or coherent as a written one.

No. As you have surely seen, the US written constitution just gets contorted to "clearly" mean whatever it is the partisan Justices decided suits their current purpose. The effect is extremely corrosive - they even decided it means their guy is above the law.

I agree that using a better voting system (STV) is a meaningful benefit and worth replicating elsewhere, but I don't agree that having a written constitution is better. I think Ireland would be in roughly the same place if it had the same arrangement as in Westminster in that respect.

For example when Ireland wrote a constitutional amendment saying abortion is illegal under basically any circumstances, the people the Irish were electing would also have voted against legislation allowing abortion, but by the time the poll was held to amend to say abortion must be legal, the legislators elected were also mostly pro-choice. So if there was no written constitution my guess is that roughly the outcome is the same, in 1975 an Irish woman who needs an abortion has to "go on holiday" abroad and come back not pregnant or order pills and hope they're not traced to her, and in 2025 it's just an ordinary medical practice. Maybe the changes happen a few years earlier, or a few years later.

Edited: Clarify that the abortion prohibition was itself an amendment, as was the removal of that prohibition.

The power of a constitution is in it being the highest law in the land, that legislation can't just override. It's only recently in the US that there is a blatantly corrupt kakistocracy who feels free to ignore it.