If you are considering changing the platform, then Signal is a good choice if you are concerned about privacy and security.
How to move WhatsApp Group to Signal
1. Install / Open the Signal application. Link
2. To create a group, click on the three vertical dots on the top right corner of the app, select “New Group”
3. For creating a group in Signal, you will need to add at least one contact to set up a group.
4. Pick the contact to get started. Tap on the arrow to continue.
5. Enter the name for the group, click on the “Create” button.
6. Now click on Group Settings and tap on Group Links and turn it On.
7. Copy the group link and share it to all the members of that WhatsApp Group
While this lets your existing WhatsApp Group users join the newly created Signal group, you won’t be able to transfer chats and media files from WhatsApp to Signal given that both are totally different and independent platforms.