Small correction, but there are actually four states (CA being one of them) where you can avoid law school by what is called “reading the law”. It entails more or less doing an apprenticeship with a practicing attorney or judge and meeting certain requirements.
The bar needs to be broken out into separate tests that credential different aspects of practicing law. There's no reason a criminal attorney needs expertise on securities law unless they practice in that field.
Do any other nations do that? Much of the UK splits barristers (trial law) and solicitors (non-trial law) but I’m pretty sure that’s a historical relic not a designed split to make each easier to learn and practice.