I agree with the OP and want to say that Nintendo marketing, in general, has a lot of room for improvement. Here are some things they could be doing.
1) RFA needs to be advertised even more and especially toward non-gamers. This is the successor to Wii Fit and in a world where a lot of gyms are often closed, there is a big potential market of non-gamers who would buy a Switch just for RFA. I also think Clubhouse games could also get extra marketing like this especially highlighting games like bowling with motion controls.
2) They need to regularly (maybe quarterly) spotlight their most popular indie games. I looked back at some old indie directs are found that at least half of the indie games that I like were not even in them. A lot of times the indie games that become popular are not what you'd expect.
3) They need to list all Switch million+ sellers and not just first party titles. I'm sure they need to get permission from the 3rd party publishers, but they need to make the effort to get this permission. Their financial reports will say something like "and X number of other titles sold over 1 million units." What are those titles? They don't even need to give specific numbers. Make it more of a "either you are on the list or not" situation. Just doing this would spotlight the most popular third party titles even more.
RFA marketing on a bigger scale was pointless when the available supply was limited. Nintendo already told their investors that they'll increase marketing spending, so that's that. I don't know how it is in your country, but in central Europe Nintendo runs exactly the commercial for RFA that you describe and on the appropriate TV channels during appropriate hours. Clubhouse Games doesn't get as much attention, but that's understandable due to its lower sales potential.
Nintendo posts monthly bestseller lists in the Switch news feed. Bestseller lists can also be looked at on the eShop. It isn't hard to find out for gamers which indie games are the most popular ones.
I doubt that many gamers would care about more comprehensive sales updates. These things aren't given attention more than four times a year at most.