Your mortgage rate should influence your investment strategy. Here is a simple framework: if your rate is 7% or higher, prioritize paying down the mortgage (guaranteed 7%+ return). If your rate is between 5% and 7%, consider splitting extra cash between mortgage payments and investments. If your rate is under 5%, focus more on investing and keep the low-cost mortgage.
This framework balances the guaranteed return of debt reduction with the potential (but uncertain) returns of investing. It also considers that a 7%+ mortgage is expensive debt that should be eliminated relatively quickly, while a sub-5% mortgage is cheap debt that can be carried while your money compounds elsewhere.
Your personal risk tolerance, time horizon, and financial goals should override any general framework. There is no single right answer for everyone.