Connectionalism matters. As US evangelicals became more and more congregational (UCC, Southern Baptist, non-denom, etc) & less connectional (Episcopalian, Methodist, Presbyterian, etc.) they lost their cultural influence. Change happens through institutions, not local bodies. https://twitter.com/churchstate/status/1286274411465715713
I was raised UMC. As a kid, when the North GA Methodist Bishop (seated in Atlanta) called the mayor, the mayor called back. Why? Because he didn't represent one local church, he presented 800 churches, important universities, etc. Why do evangelicals believe differently?
It's likely why church-led US racial reconciliation movements haven't yielded much. You can't have effective racial reconciliation outside of transitional justice working through institutions. You can't get connectional outcomes through congregationalism. https://hackingchristianity.net/2008/12/why-connectionalism-matters.html
The National Association of Evangelicals could be a massive force if all of congregational churches joined it and funded it. The Southern Baptist Convention aren't even members. So we can't expect different results ignoring history & what's been standard. https://www.nae.net
BTW, while the Protestant mainline church is dying, their institutions still leverage massive influence because decision-makers recognize institutions. The National Council of Churches *still* influences public policy. http://nationalcouncilofchurches.us