I would say cut them some slack. If they are new, they are eager to share their work and probably have a few items ready to show before joining. In future they will probably only have new items, which will likely appear one at a time.
Also, they might not be fully aware of the bumping effect of replies, and are responding to comments out of politeness. It took me a while to get the hang of things like tagging people wiithin posts, or quoting, both of which make it easier to include multiple acknowledgements in one post. It also took me ages to fathom the reaction emojis, so you can just acknowledge a reply without posting.
A final factor may be that they are used to conversational platforms, which is catered for here in the various 'chat' and discussion areas, but perhaps not appropriate for RFI. Again, this may well be just lack of experience of how the site works.
We were all new once, compared to most I still am, and being new can be awkward.
Matt