"watching" with a dedicated team vs "waking up everyone in engg because things are on fire" are two very different things.

Besides, size doesn't work that way. The larger the organization and the more complex the product is, the higher the chance some unexpected interaction will occur. There are processes and automation that can mitigate this, but one can never be completely certain.

Not even the aviation industry has mastered that.

Just because they can have people come in on weekends to fix things doesn’t mean they like doing that.

I know many “mature” software platforms that do not deploy on Fridays or off hours at all