A lot of users (Product Owners, Designers, Community Members, etc.) do not use or watch Gerrit, but they do use Phabricator.
Developers will sometimes ask product, design, or community related questions on Gerrit which have to be answered on Phabricator. Since the users that need to see the question do not use Gerrit, the comment has to manually be copied over (See: T132220#4128619 & T132220#4130623).
It would be really helpful if comments from Gerrit were cross-posted to Phabricator.
If possible, it would be awesome if it posted under the appropriate user's account. and if that's not possible, I think it should be under the @gerritbot account and reference the Phabricator user and quote the comment with a url to the specific comment (i.e. https://gerrit.wikimedia.org/r/c/mediawiki/core/+/422063#message-5fd9f2eb16d390c89b9df0a181fce48e78a3155e)