Context: math PhD, have been taking undergrad legal studies while I wait to see if the government thinks I'm trustworthy for a math job. They've been taking forever so I think it's time for serious backup plans and I've been mulling this for a couple of years

It's a 3 (or more) year commitment, which isn't cheap. You don't have to practice law once you have it, but if your chosen field doesn't need it, why bother?

If (1) you really, really want to practice law and (2) have the money to pay for it (because the loan-to-income ratio only works if you get a big fat job in BigLaw, and a short list of other exceptions), yes. Any other reason and you don't have unlimited income? No. Retired BigLaw staff here.