I'm not confident that the average flutter app will have fewer memory leaks than the average web app, I've come across an API that seems to encourage leaks already (https://github.com/flutter/flutter/issues/10623#issuecomment-790940759) but the project probably has a lot more agency to address the issue than web browser maintainers do.
Merveilles is a community project aimed at the establishment of new ways of speaking, seeing and organizing information — A culture that seeks augmentation through the arts of engineering and design. A warm welcome to any like-minded people who feel these ideals resonate with them.