I'm sorry to hear that you're experiencing this issue with the "Ready for more?" splash screen in Illustrator. I understand how frustrating it can be to have this pop up every time you open the application, even though you're not interested in upgrading.
Would you mind sharing the screenshot of what you see on your end? I will check with the Illustrator product team if there is a way to turn this off. Also, please confirm your Illustrator & OS versions.
I will be looking forward to your response.
Let me know if you have any further questions or concerns.