Validation should not be skipped for instant gratification. There are forms of automated validation and this gives us a test result and confidence in the integrity of the work.
Or when someone assumes that something got done and reports it as such only to find out it wasn’t. Skipping validation and reporting things as truth when you actually don’t know is a gamble of your reputation and the success of your endeavor.
I have seen too many major issues where revenue is directly impacted because someone assumed the code did something one way or reacted in another. This is why we have UAT and QA.