Maturity is not sourcing

Once you know the outcome and the capability required, you can consider how to obtain it. You may buy a product, assemble existing services with internal workflow, or build something distinctive.

Keep that decision separate from maturity and priority. A strategically important capability doesn't automatically require custom software. An ordinary one still needs sensible governance if you obtain it from a vendor. Clarify what the business needs, use evidence to support the decision to proceed, and then choose the source that fits.