That helps with storage, but still is larger than a bigint, and doesn't help with the random distribution of data. I believe newer versions of MySQL have a data type for this.
MySQL doesn't have a UUID type, nor 128-bit int type. But MySQL 8 does provide functions UUID_TO_BIN and BIN_TO_UUID, which make it trivial to convert between the human-readable string representation of a UUID and the more efficient BINARY(16) representation.
MariaDB now has a native UUID column type as of MariaDB 10.7. This is brand new -- 10.7 had its RC release in Nov, not GA yet but very soon I'd imagine.
If you use a type1 UUID, you shouldn't have quite so random distribution, particularly if there's only a single machine generating the UUIDs (which admittedly, kind of misses the point, but alas is done all the time).
Well, you probably shouldn't cluster on a UUID, but it's not really a great idea to blindly cluster on a sequential id, either. You should cluster based on how you query the data to minimize I/O.
MariaDB now has a native UUID column type as of MariaDB 10.7. This is brand new -- 10.7 had its RC release in Nov, not GA yet but very soon I'd imagine.