
There were a lot of intermediate systems that came out in the middle of a generation that don't fit in with the big dogs of the generation and didn't match the power of the following gen's mainstays. In the 80s and 90s, those systems came from would-be rivals, but over the last ten-15 years they've been mid-generation refreshes from the Big Three.
Examples would be the Atari 5200, which came out around the time of the Colecovision, so the CV and the 5200 could be seen as a mini-generation between the 2600, Intellivision, Odyssey2, and the Bally Astrocade. The Atari XEGS, which was an Atari XE repackaged as a console, and the 5200 itself was based on a simplified version of the architecture thaf powered the early Atari 8-but computers; it very was easy for hackers to port 5200 games to the 8-bit computers. Atari's third gen entry is generally considered to be the 7800, which was outclassed by the NES and Master System. The CD-I, 3DO, and Jaguar, which were positioned as more powerful competitors to the SNES and Genesis, yet were badly outmatched by the Saturn, PS1, and N64. The Wii U, which was not as powerful as PS4, X1, or the Switch. The PS4 Pro and the Xbox One X. The Switch itself is competing against the 8th and 9th generation Playstations and Xboxes.