Android’s notifications are actually a great concept for their simplicity - every app with notifications is one icon in the status bar - that’s being somewhat abused by a feature added in later versions of Android: background activities have been increasingly limited with every major Android version to save battery, except for apps with active notifications. Hence the seemingly unnecessary notifications by apps that use them just to stay alive.

Plus the sheer number of apps that want your attention keeps increasing.

As a workaround you can ask Android not to show certain types of notifications from certain apps (except for some system apps). Swipe the notification slightly left or long-press it, and there should be a cog icon or button that takes you to the available options for the respective app. Or depending on brand and model of your phone, go to Settings and search for “notifications” for additional options.