There is truth in it, but if you take it to its logical conclusion you could say that any additional equipment or even skills in tangential activities is a waste of time and resources. If the ultimate goal is to become a better cook then any knives past one or two knives is a waste, they don’t even have to be particularly good knives just decent enough. More or better knives will not make you a better cook. Honing your sharpening skills past the basic ability to keep your knives sharp is a waste. Buying more stones to sharpen is a waste, pans, pots, etc. In every case after some basics that allow you to cook comfortably enough all other equipment and unrelated skill improvement is a waste and your time and resources would better be spent actually cooking.Actually, I do think there's a grain of truth in Dan-'s point... If you want to level up your cooking, it makes sense to spread your investments, instead of having a very 'unbalanced' set of gear. Yes, total amount of pans or their price isn't going to make you a good cook on its own, but on the low end you do run into a point where lack of pans (or low quality) can limit your options / make it a struggle.
So it makes sense to invest at least a little bit into that section of cooking instead of doubling down on the diminishing returns territory of knives. Of course the same argument can be made for all aspects of cooking equipment when offset to the cost of buying good ingredients. Once you hit a certain minimum level you hit diminishing returns and any extra money is probably better spent on better ingredients if you want to have a better result.
Luckily though a lot of good quality stuff is pretty much a life-time investment, so from that perspective stuff like good pans is a 'cry once' affair.
Some people bought better knives to become better cooks, some started cooking more to use their better knives, there is no right or wrong here, just whatever interests you. People with many cooking knives are more knife enthusiasts that cook than cooking enthusiasts that buy equipment to improve their lives. It is a kitchen knife forum not a cooking forum after all