That may be the case in companies without proper responsibility distinction but in those with (usually the bigger ones), not even small decisions are made solely by software engineers. They are always double checked by the Product Management because any requested change has to come from the Product Management and has to be signed-off by them. In a company like Zoom everything you are seeing in the UI isn’t the result of something that slipped through solely by the engineer but was reviewed and thought out by multiple people who don’t touch the code.