Different is not the same as better. Multiple studies show benefits for each under different conditions such as time since exposure and consistency of protection. The best fit for available evidence seems to be that getting COVID (or at least a positive test result) doesn’t guarantee a robust long term immunity for every individual. But it can result in a better long term immunity for many.

This is why it’s recommended for people to get vaccinated even after infection. They might already have robust immunity, or they might not. The vaccines are so incredibly safe and cheap it’s simply not worth the risk.