May I ask why you are looking to disable Google ReCAPTCHA on your store? Google reCAPTCHA plays an important role in your store by helping analyze the behavior of visitors to block spam from bots.
There are two settings for Google reCAPTCHA that can be enabled/disabled under Settings > Preferences. Look for the section on Spam Protection. Have you tried disabling these options already?
If you have already tried disabling these settings, but customers are still seeing a ReCAPTCHA when signing up for your newsletter, this is because there is still a regular captcha that is enabled on your store by default. This will prompt a ReCAPTCHA when there is a second visit from the same IP, which includes signing up for the newsletter. If you would like this setting disabled, you can reach out to our Support team directly for assistance. While we're not able to provide account-specific support on the Community at this time, we'd be happy to help you with request this via chat, callback request, or email.
Let me know how this goes.