Thanks for pointing that out. Yes, it's a ~2.5k difference. However, I still have the loan looming over me. Since I can pay off the loan within a year, what are other reasons to invest?
The objective reason to invest money in any case, including this one, is to generate a higher return on that money than one could earn otherwise.
If the word "looming" accurately describes the subjective feeling you have about a loan you could pay off in under a year, the subjective benefit of being debt free might compensate you for a lower net worth. For some that will be true; for others having debt that is being paid off on some schedule bothers them not at all.
One can always look back it time to see whether an early debt payoff would have provided a higher return than investing. It's just that one cannot determine in advance whether an expected higher but speculative return will outperform a known lower return.
One other thing about a 401k: the annual limit is just that - an annual limit. One can't "double up" in a subsequent year to make up for lower current contributions.