The way I see it, this hobby is a spiral. A spiral that easily gets out of control. If you have a system consisting of an integrated amp and speakers totaling 500 bucks, a DAC that costs a $129 makes sense, and you won't hear much that a 10k DAC brings to the table in such a system. You won't hear what an expensive power cord can do. Or speaker cables, etc, on and on. At this point in your journey, you likely haven't heard a lot of other systems, or understand fully what is possible at different price points, and how important setup and room treatments are, etc.
You continue to learn and grow. Once you upgrade your speakers to something on the next level, say a few grand, your amp or your sources start showing their weaknesses. You upgrade to amp separates worth 5 or 10k, and then you realize you need to upgrade your DAC. It never ends, but as you continue to upgrade, you understand better what you are after, what is possible, and what it costs.
At a certain point you start getting into cables and even if you start out slowly you do hear some differences, maybe not all the time, but it starts revealing more that your components can do. Once you start hearing what a good power foundation can do, and you've gotten to a certain level of gear and understand how to set it up properly and have your room treated, you are fully off to the races like most of us on this forum.
When someone says all you need is a $129 DAC, or lamp cord for speaker cables, or cheap power cables, they are right, in the context of a beginner. However these cheap components have limitations and you need the experience and the system to expose that. A lot of the time, when you see such statements on social media, it's helpful to remember that we all started somewhere and to those people, it does make a lot of sense to have a $129 DAC. They will spiral out of control just like we do, eventually
