Bitcoin's scarcity makes it a valuable asset. But there are many other other things rather than scarcity that affects the value of an object. With the rapid advancement in technology we can expect a more valuable asset or object than Bitcoin but not because of its scarcity but because it will solve a major problem like Bitcoin Solved. So yeah, I think there can be a more valuable asset than Bitcoin but it doesn't seem it will come in Near future of 150-200 years.