But all bitcoin early holders are also profiting from delayed seigniorage. They obtained coins which were easy to mine (money that was easy to print) and it is now worth much more. All deflationary currencies bring delayed seigniorage to their early holders. In fact, almost all of bitcoin, and almost all of crypto, is living off the speculative effects of delayed seigniorage (cheaper printing than later market price).
There would have been a way in bitcoin to make seigniorage disappear: namely NOT INCREASE THE DIFFICULTY more than Moore's law, and keeping the block reward constant (tail emission). You would then have a coin of which the value would remain constant, and equal to the (economic) work spent on it. That is, if on average it would cost, say, 10 cents to mine a bitcoin in cost of proof of work, that would be about its market value, and would remain so, because if it increased, people would simply mine more of them, instead of paying more for them. All of its seigniorage would be burned by PoW. This is not the case in bitcoin, because as bitcoin's value is appreciating, the early mined coins were made with much less mining costs than their value, being similar to printed money in a way.
But bitcoin was not designed as an ideal money keeping its value almost constant, it was designed as a deflationary speculative asset, with delayed seigniorage, to profit early adopters, and blow a greater-fool bubble that way.