Fwiw, if you actually use a 4" adjustable wrench, treat yourself to a Knipex 5"/125mm pliers wrench. Everything a 4" adjustable can do, the 5" pliers wrench can do better. And this is coming from someone who used to use a Snap-On 4" adjustable at work occasionally.
If its vintage, says Snap-On on one side and Blue-Point on the other, and USA, it was made by Diamond Tool & Horseshoe for Snap-On.
The Knipex pliers wrench has jaws which compress the nut or whatever you’re trying to turn.
For heavy steel and brass nits, etc. which are very stiff, this is fine, and simply makes the Pliers Wrench grip well.
When trying to use a pliers wrench on nuts that aren’t as stiff or sturdy, like the zinc nuts found on plumbing fittings, having the Pliers Wrench jaws compress the nut is problematic, and can actually make it much harder to turn the nut, or possibly cause the nut to get contorted.
With a regular adjustable wrench, the jaws are fixed in place while turning the nut, so pressure is only applied to the nut corners.
I still like the pliers wrenches, and wouldn’t want to be without yhem, but they’re not always the best tool for the job, or better than regular adjustables.