In Topics, downloads and links do not behave the same way like they do on resource boards.

When you drag a link block to a topic, it lives as a single, isolated link.  There's no opportunity to add additional links to the same block, or organize them into sub categories, so you have a lot of links there are many many link blocks.

Links and Downloads on resource boards act exactly the same way in that you can create separate link and download blocks if you want, but you also have the option of adding many to a single block and organize them.

Not sure why they function differently within topics, but it seems to me that it should all be the same.