Tape quality is always dependent on the tape speed and the tape width. When you increase either, you can make better recordings.
Most consumer reel to reel enthusiasts use quarter-inch tape which is twice as wide as cassette.
The speed of reel to reel tape recorders being variable, typically starts at twice that of cassette (1 7/8 inches per second, IPS) and can be doubled (3 3/4 ips) or quadrupled. Semipro and Studio professional tape recorders can run at even higher speeds, up to 60 IPS