The biggest factor is probably that once people got comfortable watching from home, the friction of getting to a physical location every week just felt unnecessary - especially if they had kids, health concerns, or long commutes. Your situation isn't unique; lots of churches are struggling with this exact thing. Some congregations did stay mostly online because their communities were geographically scattered to begin with, or because streaming actually let them reach way more people than their building ever could. The tricky part for churches trying to pull folks back is that you're competing against convenience, which is a tough sell. Are you finding that the people who do show up in person are different from who watched online, or is it more that the total numbers just dropped?