I read that using bridges lets you access websites that (soft)block Tor (e.g. Google) and it really does, but the bridge is the first node in your circuit so why don't website block based on the exit node, and how can they see my first node?
Bridges don't hide the fact that you are using Tor from the website you are visiting. Full stop. End of story. That's not how things work.
If you started using a bridge and suddenly the site seemed to stop blocking you, that's a coincidence.