I find it hard to believe the same amount of investment will be made into a decentralized web index, precisely for the reason that it cannot be monetized.
Also there are state-funded open search indexes, like the European Search Index.
So it can be done realisticly, even though the massive private search index lobby push as hard as they can to deny it.
[0]: https://tom-nicholas.com/blog/2025/science-needs-a-social-ne...