Some fast-food places in the US went drive-through-only in 2020 and are still that way. I think if you're in the kind of rural or suburban place where almost everyone drives almost everywhere, then the drive-through does the majority of fast food business anyway, and many people who would have gone inside will switch to the drive-through rather than not buying your food, so the cost savings from not having to hire more staff to maintain the dining room might make up for the lost sales. Obviously in an urban area that gets a lot of foot traffic, this would not be the case.