While L4 is terminal at Google, it's still not particularly high achieving for 6 years of career. Google also doesn't make it easy to jump from L4 to L5 either,

While L4 is terminal at Google, it's still not particularly high achieving for 6 years of career. Google also doesn't make it easy to jump from L4 to L5 either, so OP may feel like they're stuck in a rut because of that as well.