The tradeoff is not so clear cut. When disassembling more parts, more can go wrong. This is true for the MBP, and especially for the iPhone. Screws can get damaged, misplaced or swapped, which can be disastrous because they have different lengths.
If the whole procedure takes a long time, people will get impatient and probability of errors increases.
This is why I still feel the fishing line method, combined with low quantities of solvent is the least risky option overall.
You don't have to follow each step, but if you don't know any better you should.
taking shortcuts just leads to sloppy outcomes, like any repair method.