So, I have figured out that one of the reasons that I interact less with Mastodon is that I never know that there are interesting replies to read. This is true whether I am reading in Pinafore (which doesn't display reply counts at all) or the Mastodon web app (which at least displays "1" or "1+").
The mobile apps I use do this somewhat better, but since I've learned you can never be sure you're seeing all replies, I'm less likely to say something in reply, for fear of unwitting repetition.
@crschmidt Note that lack of quote-toots is a question of your instance: ActivityPub does have support for them (instances will IIUC at worst render the quote as a link if they don't support the thing at all), and some instances do support publishing quote-toots.