Let's start with number 1, since you go wrong from the get go. Baldur's Gate is not a person. It's not a floor wax nor is it a dessert topping. It is a city located on the Sword Coast of the world Faerun, and part of what is consdidered the Forgotten Realms. BG1 involved events occurring in and around the City of Baldur's Gate. BG2 involved further events occurring in and around other cities areas of the Sword Coast, but was referenced as BG2 because it continued the story of those in BG1. BG 3 once again involves events occurring in and around the city of Baldurs' Gate, hence the title.
I live in New York. New York existed 100 years ago, and stuff happened here - I just wasn't around for it. I am around for stuff that happens now.
Your character was not around for the stuff that happened in BG1 and 2, 100 plus years ago. Your character IS around for the stuff happening now. No matter how hard you stomp your feet, and how blue your face turns from holding your breath, you are NOT going to change these simple facts. If you insist on playing the continued adventures of the featured character from BG1 and 2, you will have to create your own game. That is not what this is, nor what this was advertised as. It is 5e based adventures of a new protagonist in the area of Baldur's Gate. Don't like it? Don't buy it. And certainly don't complain that an EA game advertised as a small, partial testing ground isn't the complete end product you fantasized.