I had a pair of $40 knives from ikea that lasted years (more than a decade, maybe close to two). They were moly steel so they didn’t loose edge quickly, and had decent balance.
I eventually upgraded to Whustoff ikon classics (the POM handle,) for the 3 knives I use (8” chef, boning, pairing.)
The reality is you can sharpen a shitty Walmart butter knife to a razor’s edge very easily. Being sharp doesn’t make a good knife- it’s the steel quality that affects edge retention; as well as the balance and the grip’s contour/shape; the stiffness and thickness of the blade, etc.
Imo, the cheapo ikea knives performed just fine. For their value… they’re quite probably better than whustoffs, no question. They’re both made with reasonable quality steel, both full tang, with similar contours in the blade profile and handle, etc.
But if you consider side by side, the whustoffs do perform much better. It’s not any one thing- the balance is better, the blades are thinner, stiffer where they they’re supposed to be, etc.
There are a lot of small things that add up to that. The distal taper, the taper from spine to edge (in the ikeas they’re flat in both directions,); the steel is better and holds edges longer while being more easily, less strain on my hand;
Ultimately, you don’t need whustoffs or anything expensive- and a lot of your expensive knives are shit knives with marketing (especially “japanese” knives of dubious provenance).
But if you can afford them, they are better. Especially if you cook a lot. If they’re “better enough” to justify their cost is a personal decision. My mom uses Costco steak knives for everything. (And in part because they can’t keep knives sharp so don’t see the point. They float around the sink… get stuffed in the dishwasher, etc,)