Going with the flow

I have recently started speaking to my ex (dates for 5 years) and we’re seeing where it goes. My ex is not financially stable and in a sense lacks ambition. He wants me to wait for him to get his life together which he thinks will take 5 years. We’re in our late 20s so I’m against this. He used the fact that I’m in school changing careers so “we’re both technically working on ourselves.” I just don’t want to put all my eggs in a basket, especially if I want to eventually get married and start a family. Am I wrong for wanting to date other people in the process? Should I stick it out and see what he accomplishes in the months to come?