Because each and every coin into existence comes with a product and unique value.
This couldn't be further from the truth. Almost every new coin or token that is being launched doesn't have a working product. Hell, most of them don't even have a working team, working code, a whitepaper, a github, or a wallet. 99.99% have absolutely no value whatsoever, let alone a unique value, and certainly no real world use.
Almost every coin created these days is designed for one thing and one thing only - to make its creators some easy money. They are relying on newbies and the gullible to throw money at their project so they can make a quick buck and disappear.
You are obviously exaggerating the negative aspects of new coins and tokens. There are a lot of useful and promising projects that are emerging. Also many of them have a working product. Yes, and especially worry about it is not worth it. All unnecessary and unclaimed coins and tokens will eventually leave the cryptocurrency market. Therefore, let everything go on as usual. We still cannot change anything in the process.