Making a living as a CNA can be done, but its not easy. Even if you do make a decent amount of money its the wear and tear on your back that makes it tough to make a career out of being a CNA.
RNs experience some wear and tear on their back as well, but they are a lot better compensated for it financially, and RNs can often find jobs that require little to no heavy lifting, where as with a CNA its going to be a big part of the job no matter where you work. Sadly a lot of the lowest paid CNAs work in places where they are doing the most heavy lifting, mainly in LTC.
I would recommend that every CNA that can do it go for more medical training, even if you like being a CNA. If you can, try to take one class a semester even if you arent particularly book smart and struggled in high school, you should still be able to take a class like medical terminology
one semester, beginning A&P another, and maybe some MA classes, and in a couple years you will possess skills that will enable you to branch out from being a CNA, or stand a much better chance of working as a hospital PCT.
From there you can decide to go on to be an RN, or not. Its not for everyone as there is increasing competition for school seats, and its expensive and time consuming, so its unrealistic to expect that every CNA is going to become an RN.
Ive been non commital on RN at this point, just adding gradually to my skill set. Getting my EMT license one year, taking phlebotomy classes another, A&P this year, while still working as a CNA and PCT. If I was 18 again I would just focus on becoming an RN, but life didnt turn out that way.
God bless people who can make a career as a CNA, but I dont see it as a long term job prospect for most people, its just too hard a job for too little money, and its a shame, because being a competent CNA takes a fair amount of skill and dedication, not everyone can do it, so I feel some CNAs are wasting their talent by not continuing on.