Career growth comes in many forms, many of which aren’t obvious early in a career. It’s understandable to only see growth through the lens of a ladder - individual contributers becoming managers, then directors, and so on.
This is especially true in product management where I’ve spent the majority of my career, but applies everywhere. In my experience I’ve seen growth happen across a number of dimensions:
Growth through people management. This is the common, well trodden path. Individual contributers are often promoted into management positions where they lead teams of IC’s. This can work really well because IC’s have domain expertise - they know the work, so they should be able to manage a team doing that work. In terms of the lattice, you’re moving from the domain of direct output to that of individuals and teams. Where it falls apart is when individuals don’t realize that they have to exercise their leverage through people - and either over manage their work or under manage their output.
Growth through increased scope of responsibility. This is often accompanied by the first, but sometimes an IC can get promoted into a senior level position with a bigger playground. They have demonstrated their ability to make change and are given a bigger playground. This is best suited for folks that don’t have an interest in people management, or those that want to stay close to the work but still see professional growth.
Growth through new challenges. Professional growth is accompanied by a certain amount of discomfort in the work. Often, putting people in an entirely new line of work outside their expertise creates growth. People have to want to grow in that new area (true for everything here), but especially so in this type of transition.
Growth through operational responsibility. This is a specific type of the above, but worth calling out. IC’s that are particularly process oriented can become a service layer to the rest of the team. It can sometimes create a new role altogether, and it’s a transition I’ve seen a few times.
Ultimately, going from individual contributor to any of the above options doesn’t restrict anyones path. It’s important for managers to find how their team wants to grow and create a path that’s appropriate for the individual.