The maps shows that the countries where women may serve in military combat roles are mostly European. It’s permitted in all Scandinavian countries, which famously have the narrowest gender gaps in the world. It’s also prevalent in the Anglosphere, where it’s allowed in Canada, Australia and New Zealand, with the United States and the United Kingdom the last hold-outs.
Otherwise, the only other countries that allow women in combat are Israel, Eritrea and North Korea: an odd mix of nations that use conscription to maintain large militaries. In all three, cultural solidarity with the military and history of armed conflict may play the biggest roles in that particular form of gender equality. But I’m not sure what may have led South Africa and Pakistan to break from their regional norms and permit women to fly combat aircraft.