"The Scrum Team consists of one Scrum Master, one Product Owner, and Developers. Within a Scrum Team, there are no sub-teams or hierarchies. It is a cohesive unit of professionals focused on one objective at a time, the Product Goal." Each of these roles are important and should not be dismissed or missing from the team. It is recommended that the Agile Team positions be filled by contract partners (ADOs).
The heart of the value delivery is built on the Agile Team 1. From the Scrum Guide 2:Scrum Master
Product Owner
Team Members/Developers
References
2 - Scrum Guide https://scrumguides.org/scrum-guide.html