I’m not sure I agree… Or more precisely, it depends. !bapcsalescanada is an example of a community where there is value in reposting content from Reddit over, where the value is getting the coverage of deals. On Reddit, a small majority of users actively seek and share deals. If those users don’t move to Lemmy, that community is dead, period. No amount of enticement will introduce new content.
The secondary value now is that, previously, many users had to go to Reddit for that content, because that content isn’t available on Lemmy. Reposting isn’t just to kick-start user engagement, but is also a retention tool. Users don’t need to go to Reddit to fetch that info anymore. I know that was the case for me.
I understand the consequence of Lemmy being a mirror of Reddit. And yes, over reposting is detrimental. This is where reposts need to be strategically applied where it makes sense.
Ideally you don’t want a blood transfusion. But in specific circumstances, a blood transfusion kick-starts the healing/growth process.