GH did not really support automated base change (after merging) not that long ago, so doing this as stacked diffs/prs there was quite annoying. I guess that's why people tried to avoid it for a long time? I know I did some weird PRs in the past just to keep them independent. It could still be improved today (why is main the base when the branch contains an existing PR? adjust it automatically, please!), but it's not a big issue anymore.
Also this workflow is excruciatingly painful if you need to make a change or add a commit to an earlier part of the “stack”. Now you have to manually rebase everything after it one by one by one.
