All you got to do is get an agent, and then everything else will fall into place!
Above is the mentality of many aspiring actors and voice actors, but the reality is not so simple. Despite an agent being a major asset that is amazing to have in your corner, they are not an actor's single key to success.
Agents often operate in specific regions, generally around the geographic area of where they are located. It is common for actors to hold a variety of agents across different regions to get the maximum coverage of opportunities.
Agents will filter and send you roles they think you are appropriate for you, if there are not appropriate roles in that region they will not all of a sudden magically appear.
Even though on paper an agent works for you, it is not a one sided relationship. They have expectations of you to represent the agency well in auditions and be responsive to their requests.
Agents will likely never be your only source of work. Further especially as a VO most agents will allow you to seek work out on your own when they are as well advocating for you, although some may require you to give them a cut if you find work in their region.
At the time of writing this, I am honoured enough to maintain four different sources of representation across major VO geographic areas. My agents have been great teammates and I strive at every opportunity to be the best teammate I can be for them as well.
At the end of the day, when you acquire an agent, which is a big step, be prepared to work as hard for them as they are working for you! Like working well with audio engineers and directors, it takes more than just you to be successful in this industry.