Re: send email to people who didn't update
Is this using the Approvals system, or simply in SharePoint only?
If you're using the Approvals system, you would need to set your approval action to time out after 5 days and have a section of your flow run if the approval action times out. This would need to get the items of that row, filter the ones where the approval column is still pending, and send the email out to those individuals.
If you're only using SharePoint and updating columns as someone responds in some fashion, whether it be through Power Apps, an adaptive card in Teams, etc., then you may want to separate the two flows. You can have a secondary flow that runs once a day, sets a variable to something like
formatDateTime(addDays(utcNow(),-5), 'd')
to get a specific date 5 days ago, and use that as your Get items filter query. This will return the rows where the created date is equal to the variable date. You will then need to separate out the ones where the appropriate column hasn't been updated, possibly through a Condition action.