The recommendation you hear a lot on that board is that if you are doing a maths degree you should also study something else somewhat complementary (comp sci is a popular choice) and hope to find employment in that field. I had honestly at some point considered doing a Ph.D in Maths but upon further consideration - and realizing then that my future would likely involve low pay, excessive travel, low job stability, and a crushing amount of work - it just seemed like a very sad proposition.