I get what you're saying but:
-your shoes appear to have a slightly raised heel, it's not unreasonable to assume that the heel is also slightly cushioned
-even if the sole is completely flat it is still very likely that it is cushioned, that will give you less stability and will absorb some of the force that you apply when squatting - kind of like squatting on a matress
-weightlifting shoes have rock hard soles, no compression at all. Chucks have very thin soles, but there is some slight compression. Whether it's enough to make a difference is debatable, personally I wouldn't spend a couple hundred dollars on flat soled weightlifting shoes when there are much cheaper options.
When I was debating whether to get weightlifting shoes I tried squatting in front of a mirror barefoot and then with a pair of boots on (with a raised heel) to see the difference, it was much better with the boots. Just an idea.