If I want to notify somebody, I use the option to send them a message. Be that either a text message or one just containing the emoji one could also react with. If I just want to let them know that I am looking into something they requested from me, I am reacting to their message using something like the eyes emoji, marking the room as unread and only notify them once I figured something out that might be relevant to them.

I also feel more encouraged to react to messages in a group chat knowing someone else's phone won't just vibrate all the time just because I think their message was funny right when they were just about to fall asleep.

I personally appreciate my matrix bridge for fixing that signal flaw for me.