Young singers, no matter how advanced their technique is, or how mature sounding their voice is, must learn to be patient. If you want a long, fruitful career that is. I started singing professionally when I was 21, but I didn't start singing opera until I was 26, and not full time until I was 29. It's true that the lower male voices take longer to develop and mature, so basses and baritones have to be even more patient than the higher voices. I have had students who are in their teens who are in a hurry to become professional singers with big, full voices. That pathway leads to misery and a short career in most cases. I can't remember the number of my young colleagues whose careers were severely truncated by taking on roles that were too big, too dramatic, too high, too low, or just too much.
The problem is it takes years to develop a reliable, sound technique that will see you safely through thick and thin. It's all very well to have a natural talent and exploit that, but when something goes wrong and the wheels fall off, you don't have the experience or the technique to save yourself in a difficult situation. It only takes a tricky performance with a head cold to set you back months, and in some cases it can be the end of your voice and career due to damage sustained from that one performance.
Sadly for all those desperate to climb the ladder quickly, it's a big risk to do so too early. My belief is that a minimum of 5 years of technical study, regular practice, stamina building, becoming a better musician and an educated student of your area of interest is necessary. That includes language study and a lot of listening to the best in the world in your vocal type as well as other types. Learn what the standards are and try and figure out how some singers do what they do. At some stage you will be ready to work professionally, but don't be tempted with roles that are wrong for you. It's better to say no than do a bad job, which can damage a fledgling reputation before you even get started. Song recitals and concert repertoire are ideal for young singers. You learn a lot about performing under pressure, performing with an orchestra, and feeling very alone and naked when it's just you and a pianist. My advice is to leave the pressures and stress of the opera world until you are in your mid twenties at the earliest.