The content porting really only means something when it's not overwhelming and the person doing the content porting is actively planning to participate in the submissions.
The easiest way to get someone to not comment on something is a wall of submissions with a fair number of upvotes and few to no comments. At this point, it's just a glorious RSS feed rather than an actual community.
Driving user growth actually requires putting in the leg work to make meaningful submissions, following-up on them, commenting on submissions, and upvoting content. All of this takes actual effort though. A bot content porting content from Reddit to Lemmy doesn't do much and for a number of people, looks much more like artificial engagement rather than any meaningfully sincere attempt at growing a community.
Some of the (World/US) News and Politics related communities are so barren of comments despite the deluge of content porting submissions, while other communities have blown up into their own distinct thing because people are making sincere, organic (enough) submissions.