We develop an open-source consent manager (https://klaro.kiprotect.com) and considered implementing the IAB framework, after seeing how it works we decided not to though as we don't want to support privacy-invasive approaches.
That said players like Google also use privacy as a strategic tool to force other players out of the ad market. Since Google can easily get first-party cookies into > 95 % of all browsers they won't be impacted by the restriction of third-party cookies. As most users go through their site many times per day they also have enough other signals they can use to track people without relying on cookies (user agent, IP address and a little Bayesian statistics is sufficient if you see enough traffic). They will probably continue to remove tracking capabilities that they don't need anymore from Chrome to slowly suffocate any remaining competitors that still rely on them.