Value is indeed subjective, and here it's driven by sound money (store of value, medium if exchange) properties - scarcity, portability, divisibility, fungibility, durability, verifiability, and universal demand.
Bitcoin's protocol, with its unalterable cap, incorruptible design, nation-state resistance, and support for uncensorable systems like Lightning and Nostr, uniquely satisfies these criteria, drawing global demand unmatched by any asset in history.