The Gamble
Sure the odds are low but one thing not mentioned in this is the prestige and reputation that comes from having competed at almost any level professionally. It can set you up for coaching positions and teaching pro jobs unlike anything other than being a highly ranked college player. So despite not having a highly successful professional career you will make contacts with other pros that do well and can give you the opportunity to earn money in tennis after you end your competitive years. You'll have access to a network of fellow tennis lifers and this alone is a great thing to have in your corner when it comes to staying employed or just having friends with a common interest. You'll have friends around the world so no matter what country you're in you will likely know someone or get an introduction.
Think of your time in competition as your training ground for your eventual career change to teaching, coaching, and tennis club management.