We have all these crypto-digits and we still can't set up an escrow system that can produce a patio without the contractor feeling slighted and walking or the property owner feeling cheated and suing... It wouldn't have to be fancy or even trustless... Just a mature third party that can say, yep, you completed that part of the deck... Homeowner, I'm releasing 10-25% of the funds for the next phase, do you approve? We could even roll in inspections and agorize code compliance. No more tempting 50% jackpots for unscrupulous contractors and no 50% nooses for scope-creep Kens and Karens!