From my experience of committees, they are more of a hindrance than anything.
Consensus of opinions is fine as advice but it takes someone making a decision for things to get done.
Difficulty comes maybe in that eg with Burnham declaring bigger %age of income tax going to mayors, one Conservative Mayor has already declared he'll be using the money for tax rebates not to develop eg public transport, not to develop improved infrastructure, just giving it to the wealthier constituents. If it all happens as currently proposed then that mayor's personal ideology is determining whereas I suspect even many voting for him might be business owners who need eg better parking so people can spend money in their shops, better public transport so people come into city centre and spend money rather than give it to Bézos, etc.
Councils would debate the issue and thus electorate can be more aware of the options, more accountability, constituents can lobby their Councillors, etc. Opposition can be expressed.
I find "Consensus" interesting as it really can work. WikiMedia (incl. Wikipedia) runs very smoothly using Consensus. No edicts from Jimmy Wales but as policy questions arise they are discussed on talk pages and discussion continues until such time as Jimmy consensus is reached at which point the consensus decision is implemented. And that can be for trivial things eg what convention of time formats to major things like should be start a new Wiki Project (eg WikiVoyage). It works.