What future role for the Gs in the multilateral system?

In the last 40 years, international summits have vastly expanded their role. Illustrative of this trend, the G7/8 and G20 gradually expanded to cover major world issues – until 2018 when US President Trump withdrew his support for the G7 joint declaration. This, however, does not signal the end of "Gs", whose informal nature allows them to pursue their action, albeit a fragmented, specific and less influential one.