Based on what you said I would go with @Mutt Daeng suggestion above. I still use a Redmi Note 8 rooted as my daily driver but eventually had to buy another phone to use the scb banking app as became too difficult to game it - has no Google apps on it at all.
I ended up with a Motorola, but same principles, and used ADB to get rid of or hide what I could that could not be done in Settings. So no Chrome, Gmail etc. The only specific Google apps I kept are Play Store and Play Services.
I also installed Rethink DNS (https://rethinkdns.com/ but I think also available from the Play store ) and this can help stop data from being sent out from other apps that have no need to do so. As it takes over the vpn channel I need to suspend it when using the scb app.
If you do get stuck into removing/hiding some of the default and or system apps make sure you have installed an alternative first. Eg. I deleted Chrome but had downloaded the Brave browser instead. Contacts was replaced with Open Contacts, SMS with Quik, photos/Gallery with QuickPic Gallery and I even managed to change G Board (the keyboard app) for OpenBoard Valencia. Just depends how far you want to go.
Huge no. of generally unknown open source apps on here - https://apt.izzysoft.de/fdroid/
Best of luck.