Justin Drake emphasized that Bitcoin's declining transaction fees are shrinking the security budget and could make the network vulnerable

Quotes that support claims

Justin Drake, an Ethereum Foundation researcher, claims that the security model of the Bitcoin network is broken, as transaction fees have failed to reach a significant fraction of the total network earnings, including the block subsidy.

In a detailed post on May 29, Drake argued that persistently low transaction fees on the Bitcoin network could make it increasingly vulnerable to a 51% attack, a scenario in which a single entity gains majority control of the blockchain’s computing power.