A customer community is a branded online portal that allows customers to access self-service resources, such as knowledge articles, FAQs, forums, and case management. A knowledge base is a repository of information that can help customers find answers to their questions or issues. Both solutions can help promote call deflection by enabling customers to resolve their own problems without contacting the contact center.
Verified References: Service Cloud Consultant Certification Guide & Tips, Experience Cloud Overview, Knowledge Overview

The Lightning Service Console is a user interface that allows you to manage multiple records on one screen and quickly access important information. You can use tabs and subtabs to organize your records and switch between them easily. To meet the requirement of viewing the case history of other cases for the same account when viewing a case, you can use account tabs with case subtabs. This means that you open an account record as a primary tab and then open related cases as subtabs under that account tab. This way, you can see all the cases for that account on one screen and compare their case histories. Verified References: [Tabs and Subtabs in Lightning Console Apps]

These are two recommendations that can help decrease customer wait times when they call in for support.
Setting up a Salesforce Customer Community that will allow customers to create cases online will provide an alternative channel for customers to get support without calling an agent. This can reduce the call volume and increase customer satisfaction. Creating reports to analyze call data in order to understand peak times and ensure adequate staffing will help optimize the resource allocation and service level of the support team. This can reduce the wait time and improve customer experience. Verified References: : https://help.salesforce.com
/s/articleView?id=sf.networks_overview.htm&type=5 : https://help.salesforce.com/s/articleView?id=sf.
networks_self_service.htm&type=5 : https://help.salesforce.com/s/articleView?id=sf.reports_overview.
htm&type=5 : https://help.salesforce.com/s/articleView?id=sf.reports_create.htm&type=5

Case escalation rules are used to automatically escalate cases based on certain criteria, such as case age, priority, status, or owner. Escalation rules can trigger actions such as sending email notifications, assigning cases to queues or users, or changing field values. Case escalation rules are the best approach to notify Support Managers when a new case has been untouched for more than two business days. Verified References: Service Cloud Consultant Certification Guide & Tips, Set Up Escalation Rules

Configuring case escalation rules is an approach that can notify support managers when a new case has been untouched for more than two business days. Case escalation rules are tools that allow administrators to define the conditions and actions for escalating cases to higher-level agents or managers. Case escalation rules can help ensure that cases are handled in a timely and efficient manner. Verified References: : https://help.
salesforce.com/s/articleView?id=sf.case_escalation_overview.htm&type=5 : https://help.salesforce.com/s
/articleView?id=sf.case_escalation_create.htm&type=5