Yeah, getting hit with a single or two missiles and sinking millions in a few hours doesn't seem like an overkill... Of course... That's the main reason why most navies go with 30-60 configuration. With that you can get few different missile packs depending on the mission and can over losing it during war. Or you can go into clash with wishful thinking that nothing wrong will happen.
It's the other way around - packed up Burke class destroyer is a perfect tool against weak nations. Like hitting places in Syria recently. Or going against North Korea.
A very optimistic way of looking at things I must say. Not completly unimaginable though.
Can I ask you a question - you would go with a maxed single platform with 128 tubes or two with 32-64 VLS tubes if you had to stand up against armed enemy? I think that you get increased manouverability, survivalabilty, more abundant tactics etc with exactly THE SAME firepower. Those discussions are as old as organized armed forces I assume. Think for a moment and answer. But I already know what you would rather go...
All other things equal, it's not the same effing price to build 2 ships with 64 VLS vs. stretching one out to fit 128 VLS. On the other hand, a much larger ship altogether can host a more powerful radar, electronics, and perform additional functions like helicopter operations; it might be able to detect 2 smaller ships long before they can see it and strike them before as well. There are many advantages to increasing missile load. Not only can you can take on multiple enemies, you can take on multiple missions one after the other without restocking. You can fight and have missiles in reserve to protect you as you return to friendly territory to resupply. The last thing a destroyer captain needs is to be in a war and have to sail 30mph for 800 miles through hostile waters with enemies lurking and no missiles on him.
The only thing I agree with in what you said is that it would be foolish to build ships with more VLS just for the purpose of one-upping other designs in VLS number. As we see, China did not do that. If the number is 112, they clearly designed 055 with its mission in mind and determined that 112 is an adequate number with a healthy margin of error. If they just wanted to get into a VLS contest with the world, they could easily have stretched it a little more to have a few more cells than Sejong and Tico. Even if the VLS number was 128, it still shows that they had no desire to be the ship with the largest number of VLS or they'd easily just increase that a little more to win instead of draw.