The three bad things in this situation are: 1. Water. 2. Cruft (dust or things like the sugar in soda). 3. Electricity.
Pure water alone on a circuit board with no dirt or electricity has a good chance of doing no harm as long as it dries out before use.
Even if you spill pure water on a laptop there’s going to enough dirt/lint inside that it will push those things to potentially bad places.
What’s worse with a laptop is that there’s a battery supplying power to certain parts of the circuit that you can’t see so you don’t know if the liquid got into those parts. Ideally, pulling all the batteries ASAP after a spill can help. But the main battery is usually hard to remove quickly, if at all. There is also the little clock battery that’s even worse to pull. (Although it will do less damage, unless it shorts then bad stuff happens.)
Aside from a battery shorting, the power levels are low enough that you rarely get a puff of magic smoke. More likely one or more ICs will fail silently and the computer pretty much does nothing. Time to sell it on eBay “for parts”. (Take the disk out first.)
The standard procedure after a spill is to power off, try to get into wherever you can to dry stuff up. (Get the tech manual for it and try to figure out how to take off the keyboard, etc.) Let dry for a week or two. Power back on under battery power. Cross fingers.