Why risk so much by skipping such a simple step that protects so much. It makes no sense to skip this step.

Whether this step is necessary depends on what you’re replacing/repairing.

This step is ABSOLUTELY NECESSARY. If you don’t disconnect the battery FIRST, you risk causing an electrical short that can very easily damage the circuit board and other electronic devices when you unplug them. The only time this is safe is if the battery is completely dead. If you were successful without doing this step, you were really lucky.