https://en.wikipedia.org/wiki/Diderot_effect
Interesting! I had never heard of this.
But I will also caution you about "buying everything new". Furniture and home decor does go out of style, and if you buy everything at once, I think that you will likely feel like it's all out of date at the same time.
When I bought my house ten years ago I bought a fairly simple headboard and new bed, but I kept my handmade dresser (that my grandfather built) and then found an antique desk. None of it matches, but because it's all from different periods, with modern linens and decor, it never feels out of date. I just like it all, and have for 10 years.
However, with my living room furniture. I did buy new about 12 years ago. Red microfiber sofa and love seat. The color, style, and fabric were super "in" back then. I can't tell you how many places I saw the same furniture for a few years. But it did not age well. Solid color microfiber with kids was awful. The furniture also started breaking down a bit. Luckily, my parents were building a new (smaller) house so I got to take their very simple, yet well crafted, medium brown, fairly modern, but not TOO modern, living room set. It can "blend" well with all kinds of decor, so I can easily change pillows or wall paint and get a completely new look for minimal cost.
I've been wanting a new media cabinet for the better part of a year, but I won't settle until I find one that is also more timeless and will last longer than the one I currently have and bought at Target 13 years ago. (Which is also something I would caution you about IKEA furniture. It might look good for a while, but it isn't going to have any longevity.)
The reason I am patiently waiting to find the "right" cabinet is that right now everything is made from fake barn wood with weird looking "barn doors" or fake fireplaces (or worse, a combination of the two). It will look hideously outdated in about five years because this faux barn wood/barn door phase has already been around for a few years.
So if you want upgrade your furniture, sure, go ahead. But don't just buy everything from one furniture store in one fell swoop. Start with finding ONE right thing. And also, is your TV really that small? Really? If it's only a year old?