Evolution isn’t a matter of “belief”, it’s an observed fact. An observed fact accompanied by possibly the best supported scientific theory of them all.
When we’re dealing with observed facts, “belief” is superfluous to requirements and irrelevant.
You don’t think this is happening?
Oh wait, have you heard of the Black Death? That instance of he bubonic plague that wiped out around 25% of the population of Europe between 1348 and 1351?
Only it turns out that survivors thereof possessed certain key genes, that were selected for by said pandemic. Here’s a nice article from a leading science journal covering this.
Likewise, you appear to be unaware that the genes for sickle cell anaemia and thalassaemia were an evolutionary response to malaria. Likewise, humans that adopted dairy farming acquired genes allowing them to tolerate lactose in cow’s milk. Individuals with Duffy negative blood antigen profiles are more common in places where malaria is present, because the Duffy negative genotype conferred some protection from malaria, though in some places, this is now changing as Plasmodium vivax itself evolves.
In the future, we may find that Covid-19 has left its mark upon human genetics, and that people with certain genes conferring some protection against the virus and its effects increase in number as they’re selected for, and produce more offspring than susceptible individuals.
As for better cognition, well, reliable measures thereof are somewhat hard to come by, but if reliable measures thereof do materialise in the near future, I suspect they’ll point to, for example, improved cognition being a feature of populations with both a well-developed education system, and a need for skilled workers that are scientifically and technologically astute. Indeed, social factors affecting cognition are already subject to significant research efforts.
So what? There are thousands of species that possess abilities we don’t have. Such as all those fish that can live underwater (33,000 species and climbing at the last count), or all those birds that can fly. But they occupy totally different niches to humans, the little fact you forgot about.