I can’t say for sure, but most pagan gods had aspects of daily life and a lot were based on nature. The earlier cat god was Mafdet, who was protector of the home and kingdom. This probably came from the same place we see dogs as protectors- they kill the vermin and animals that could hurt us or get us sick. In specific she protected against snakes and scorpions, as these were the animals cats likely killed. Mafdet was a goddess of death through executions- her associated symbols being rope and blade of which is used to kill. This made her a goddess of justice aswell. Mafdet was a powerful goddess and more serious as she was Ra’s body guard. She was shown as a cat, but also a cheetah or Lynx.

When cats became more common place and loved and more like family the god Bast (same one Black Panther is based on) kinda took over. She still had Mafdet qualities as there are texts referring to “the slaughter of Bastet” but as time went on the savagness died off. She was a little gentler and more “cat like” not so serious and scary. Bast becoming the gentler cat goddess is also shown as Bast was depicted as literal cat more often than a Lynx or cheetah like Mafdet. Bast was a protector goddess but also a goddess of women who were regarded as a gentler, sometimes even kids. She was the goddess of perfume aswell. Cats became nice and more family than just animal, so did the cat goddess.

Like most pagan religions the god/goddess was an idea or place personified. A forest god might have antlers like a forest animal. The divine version of war of course would be a warrior or a tiger or bear- animals that shown ferocity. Mafdet was the goddess personified of protection and destroying those who’d harm you. She was the personified version of harsh death or prevention of it- death by justice or prevention of death by venom. When the culture and ideas changed they needed something to personified a softer side. Cats had become more commonplace and family like. The common cat was a household pet, not so wild like the Mafdet’s cheetah which was “common” before. So the harsher Lynx goddess softened up. And what’s softer than a Lynx yet still a powerful protector? A kitty. The cat was chosen to be worshiped per se, but I think an idea was chosen to be worshiped and an animal or symbol to fit the idea. the cat best fit this idea. First “stunning, intense, and ferocious” became Lynx. Then a “gentle, beautiful, graceful yet strong” became house cat.