The 'Inbox' is a place where you can view and action out any tasks that are due as well as to get insight into the signals your prospects are giving. It might be quite frustrating if your 'Inbox' is not organized and you won't be able to find what you are actually looking for quickly.
To help organize your 'Inbox' and stay efficient, here are a few things that you might want to do.
You could create SmartLists under your sales 'Inbox' as per what you would like to see, for example:
Missed Phone Calls
Voicemails
Email Replies
Inbound SMS Messages
Events
This will help filter out the noise in the main 'Inbox' and you can easily view the above notifications via the created SmartLists.
If you would not like to see any specific notifications/in-app alerts under your 'Inbox' or in your notification bell icon eg: Email Opens, etc. you can toggle 'On' or 'Off' the notifications you would like to see there under Settings > Profile & Preferences > Notifications & Alerts.