Criticism: The community may struggle to agree on and implement necessary upgrades, leaving the network vulnerable. If upgrades fail, Bitcoin could fall behind technologically, becoming less secure or competitive.

Criticism: Limited transaction capacity could hinder Bitcoin's ability to handle global demand, driving users to alternatives. Without scaling, Bitcoin might become too slow and expensive for everyday use.

Criticism: Centralized mining pools controlling block templates could influence transaction validation, threatening decentralization. If not addressed, this could lead to transaction censorship and a loss of Bitcoin's trustless nature.