Typical Beginner Board Progression?

I'm am average beginner who's had a few lessons (7 I think) on an 8' foam board catching broken waves. I can now stand most of the time and am starting to turn. I now plan to practise what I've learnt to get slowly better at all the skills, and I understand that the progression from this is to learn how to paddle out and catch unbroken waves, which I'm looking forward to learning. What I've been pondering is when most people tend to move off a foam board onto a hard board, like I see more experienced surfers using? I have no ambition at all other than to have fun, and foam boards are super cheap to rent, which I like, but I was just pondering at what point one starts to 'outgrow' a soft board and one could progress further on something else? With other sports that I've done there usually gets to a point where you're good enough to move on to something more fun and capable, which you then usually stay on for a few years - that's the point most people stop renting and buy something. The guides I've read seem rather vague. Thanks!