So how come Mexico never built a canal across its isthmus like Panama did

Question

If it had done so,I wonder what would Mexico be like today?

Answer 1

Isthmus in Mexico is too big.

Answer 2

Perhaps because Panama never built a canal, the US built the canal and the US chose the site.

Answer 3

The Panama Canal was built by the US, not Panama and only after the French tried and failed.  It took a major power to have the resources (money) to undertake such a project.  In addition, geographic features are what indicates where a canal can be built.