That assumes the suggestion is directly comparable to an action you would have chosen yourself. What about suggestions for things where you would have taken no action, or suggestions to not take an action you would have taken? What about suggestions that include information you would not have been likely to come across yourself?

Imagine your friend is in the hospital, but you've been busy, and haven't checked your normal sources of information about your friends for a few days. You get a suggestion to send them best wishes or flowers, because they are in the hospital. This both suggests a course of action you wouldn't have considered, because you didn't know it was a candidate as well as imparts useful high priority information that you want to know that was hidden behind a feed you classified as low priority lately.

Sure, many suggestions may be minimal and not help much, but do we always classify systems based only on their average use? Sometimes it's important to look at the distribution of use, and whether there are other positive (or negative) externalities.

Currently, if you didn't know about a circumstance, people forgive you and generally understand. But, if you took the time to find out this information personally, this would have meaning, showing that you cared enough to spend the time to check. When you send flowers, the act can often have much more meaning. However, if everyone has apps that remind them of such things, you would no longer appear thoughtful, there is no longer as much meaning. We are already seeing this to a certain extent with social media.

This is the point. Is it worth the small gain in time, for the loss of some aspects of meaningful human connection/interaction?

"Meaning" always exists relative to a background. If the average person doesn't remember but you do, you stand out, and your actions have extra meaning. Just because the background decreases doesn't mean you can't stand out. You can always go beyond what the app suggests; for example, in additional to sending flower you could appear in person and sing to them.