Every person has only 24h per day. We cannot be involved in every decision that affects our lives, nor would we as a society be able to decide anything if every single person were to speak on every single topic. You can of course pretend that decisions made by people outside your direct vicinity don’t affect your life if that’s your preference, but if other people decide to weigh in on societal processes by electing someone to represent their interests that’s outside of your self-sovereignty. A representative probably won’t always be exactly in line with your position on everything, and some representatives often fall short of their mandate, but in a functioning democracy they may still help achieve an outcome that benefits overall. Democracy is a messy process of compromises, but the alternative of sticking your head in the sand doesn’t seem all that appealing either.