Your waiter gets sad because their tip will be smaller :)<p>... oh! You mean <i>browser</i> cookies?<p>If you inspect the sessions, you'll find - in general - less traffic going from your computer to external sources (especially with third-party trackers and the like)<p>you'll also <i>probably</i> get notably less personalization and/or "remembering where you left off when you come back" type interaction on a given site
It depends. Is it a French website? You can click on something that says "Continuer sans accepter" (Continue/proceed without accepting) and continue your visit.<p>Some websites have check-boxes on what you accept, and a button that says "Tout refuser" (refuse all). You can click that and proceed with your visit.
You can accept cookies but disable third party cookies. Third party cookies are the root of all evil and also the foundation of Google's business model.