I mean, GitHub and GitLab already improved many development workflows with their inline comments (as well as other features, like code recommendations) and it feels like sooner or later more improvements are bound to come!
I've found the tools are better than people expect them to be and the hard part for me is convincing junior developers that it is "okay" to start PRs "early", that they don't have to feel like they've finished a task to get comments/reviews on work in progress. There's a lot of embarrassment/group politics in the way sometimes from using "PR early" workflows.
But I agree the bigger challenge than any tooling challenge is getting the team convinced that starting a PR/MR early is not only okay but also the way to operate. Creating physiological safety around it as well as making iteration a part of the day to day workflow is a challenge but an important one.