There are no glaring mistakes when it comes to Reddit's new design. Nobody is saying that the use of white space is wrong or that having margins and padding is

There are no glaring mistakes when it comes to Reddit's new design. Nobody is saying that the use of white space is wrong or that having margins and padding is wrong. The issue is when it's not respecting anything and is simply thrown together randomly. If OP's app were to copy the same padding and margins as Reddit's new sidebar, I would have nothing to say against it. Yes, your app will do fine with minor design issues. It won't drives all of your users away. However, they might start to notice that your main competitor's app feels better and slowly trickle that way. There is a reason that all top brands have such strong design and user experience/graphic design teams. One or two small issues is fine, but they pile in really quickly. Nobody wants to complete a checkout when the entire page looks like the content of a 1995 website in a iframe. My personal philosophy is "why do anything if you are not going to do it beautifuly?". As a full-stack developer, it's easy for me to see both side of the medal. It would be very straightforward for me to simply throw components on the screen and call it a day. By the time I've programmed and integrated them in, I'm tired and only want to close the task. I have to remind myself of my motto and it always results in a better experience for everyone involved with the end product. Most of those design decisions can be done in a few minutes if you take the time (and if you have received proper training to spot the issues) and those few minutes can results in a big leap in quality.