Well, then it's not an UUID. It's just 128 random bits. If you just want to be the most random possible, you can go 256, 512, 1024, etc. That may be what you want, but you can't say UUID v4 is a "total waste" or "serves no point".
It's purpose is to never collide with another UUID v4, not to be the most unique value ever.
UUIDv4 is a 122 bit random number. Having another 6 random bits won't make them collide.
Also if there's UUIDs in your system colliding with a 128 bit random numbers then the rng is broken or your UUID generator would be great to crack encryption keys.
It's purpose is to never collide with another UUID v4, not to be the most unique value ever.