It's not about "doing something", it's about intentionality, i.e. you're working to advance your knowledge and expertise with some form of a plan, even if that plan is "try a bunch of stuff and see what sticks, then double down in that area".

Also, broad-based knowledge can be the expertise; think a general contractor who's skill is tying all the specialists together. The best software managers I've ever had came from skilled generalists backgrounds vs. incredibly deep specialists.