Why reCAPTCHA V1 IS SHUTDOWN doesn't work for the most of the SEO sites?

Google shut down their reCAPTCHA V1 API service on March 31, 2018. This broke reCAPTCHA on all websites everywhere. If you need to fix reCAPTCHA on your website because it still uses reCAPTCHA v1, it is important to upgrade reCAPTCHA immediately to version 2.  It is relatively simple to update reCAPTCHA. Delta Systems can help. Any site with a broken recaptcha using the service via the old API will need to update to one of the following options below in order to continue to be protected from spam and abuse.

reCAPTCHA is Broken – V1 SHUTDOWN ON 2018-03-31. Google shut down their reCAPTCHA V1 API service on March 31, 2018.