Schrödinger was scared of his own results, that’s what his cat is for. Not to show some profound effect about wave function collapse, but to show how the wave function must collapse (despite his calculations showing otherwise) because if the wave function doesn’t collapse, the cat is simultaneously alive and dead, which is preposterous.

However, we now know quantum entanglement to be a real thing; so, as bizzare as it sounds, the cat is both alive and dead, always. The number of timelines containing an alive cat diminish over time until eventually, dead cat is the only possible outcome. This is strong evidence for a multiverse existence. When you open the box you simply discover which universe you’re in.