The “difficulty bomb” developers had placed in the code was a warning sign to miners that one day the transition would happen, Di lorio said. The difficulty bomb, as explained by Ethhub, is intended to “freeze” the chain by increasing “the difficulty level of puzzles” for the proof-of-work algorithm, which would result in reduced block production times and reduced rewards for miners.
Source: https://www.coindesk.com/business/2022/09/12/ethereums-transition-to-pos-could-push-pow-by-the-wayside-ethereum-co-founder-says/?utm_medium=referral&utm_source=rss&utm_campaign=headlines