Benefits of having a hybrid SharePoint between (SharePoint online & SharePoint onpremises)

I am working on a new project where the customer has E5 licenses. So, they have 3 options for using SharePoint: -

1. Online only
2. On-premises
3. Hybrid

This is the first time the customer will be using SharePoint, and we need to build this basic setup for phase one: -

1. Home site for all users, to access Company-wide News/Announcements & company-wide Templates/Documents.
2. The home site will have links to each department site.
3. Each department site will have its own News/Announcement and Templates/Documents.
4. We will start by 3 departments: HR, IT & Finance.

We need to decide if we should go with SharePoint Online only, on-premises only or build a hybrid environment?

I am suggesting these Points/Approach:-

1. Since we need a basic setup and there are not any compliance requirements to use on-premises, we can do all the above inside SharePoint Online.
2. in the future if certain departments have specific compliance requirements, we can set up the SharePoint subscription server edition and build a hybrid environment with the available online

Can anyone advice on which approach to follow? and does my suggested approach makes sense?

Thanks