Actaea

But let's consider the situation. A uniform is introduced. And a poor family buys this miserable jacket and trousers for half their salary, while a rich family buys it without a second thought. But the children look the same. This eliminates a possible psychological barrier, the idea that "he's different, not like me." The social divide is partially smoothed out.

Yes, I see. Now, let's reason this way. We have two lions and one lioness in an enclosure. One lion is dominant and has essentially claimed the lioness. What do we do? Well, let's give the lions some catnip so that the second lion can have some fun and won't feel so bad. But... wouldn't it be better to separate the lions into different enclosures and give the second lion another lioness? Wouldn't that solve the root of the problem instead of doing something unclear for an unclear reason?
And it's the same here. If there's a chance that children will treat a classmate with a worse financial situation badly (although it's hard to imagine, but let's assume), then what do jackets have to do with it? Implement a social program, some kind of charity... Sponsor schools so that they can organize help for their poor students and buy clothes for those who don't have the money for it. Because that's what will solve the root of the problem, right?

Will children be "inhibited and have complexes because they can't dress in what they want"? Please. What nonsense. A child must be psychologically stable enough just to attend school. So, whoever becomes inhibited because of such trivial things will have a hard time in life anyway. Moreover, children can wear whatever they want after school.
Of course, many people don't like uniforms; that's normal. But to develop complexes because of this is an exaggeration.

I disagree with this position. It seems like all of this is trivial, but at a young age, it matters a lot, even when it's not consciously realized. Young children are very impressionable; it seems like nothing special happened, but in reality, any little thing will definitely settle in the subconscious.
I myself haven't completely forgotten my time as a schoolchild. And honestly, when you have teachers who don't exert excessive authority. When you have a semi-free school uniform (we only had to wear gray jackets, of almost any color. And no other requirements. And even the jackets themselves didn't have to be worn constantly). When you're not forced to keep a diary, but instead, you just go to school with a university grade book. All of this is incredibly motivating! You just feel like you can move mountains, you're doing something, not just some nonsense.
Against this background, the kids from schools who wore strictly identical blue jackets with identical black trousers and white shirts looked ridiculous. They were just clones...