Yes, and you use email subscriptions that way because email clients are bad at being feed readers: they effectively force you to "catch up" whenever you open them.

My point was that, with these changes, Google are making Gmail good at being a feed-reader--adding features to interact with subscription emails the way you currently interact with RSS feed items.

If your email client is good at being a feed reader, it will be sensible to use email subscriptions for things you currently use RSS feeds for.