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.
Not only scarcity but also many other things make Bitcoin value.
If only scarcity can make high value for Bitcoin, you can see many altcoins have high values while in fact altcoins have low or nearly zero values.
If you think beyond Bitcoin, you can see many examples with meme coins. There are meme coins with very high total supplies but succeeded to make their pump and dump games but still manage to hold their prices well in bear market and recovered well in a next market cycle. There are many other meme coins die very quickly even before a next bear market and next market cycle. Success of meme coins does not only come from its total supplies but other things done by their founders and developer teams.