One issue I feel with 'moving' away from iMessage, is not having text/sms messages deliver to my Mac, iPad, etcetera. If that DID work, I would turn off iMessage...
I haven’t tried, but are you sure it is not possible to disable iMessage and still keep receiving text messages on all your Apple devices?
(“iMessage” and “Text Message Forwarding” are two separate toggles in the settings for the Messages App on my iPhone)