Each Google Analytics version is just an updated reflection of the digital marketing industry. GA4 seeks to solve cross-device user identification challenges in a privacy driven times.
Server side tagging is a clear improvement over client side tagging. Server side improves data security and reduces page load times, two very important topics that directly affects your business.
Targeting is fundamental. It has changed the way marketing is understood. It has shifted marketing from mass broadcast advertising to a more smart focused Ad exposure.
The phase out of third party cookies in Chrome will mainly affect your web display media activities. Chrome aims for a sustainable and more secure web advertising ecosystem.