In my case, it basically helps me improve random read significantly. My NVMe is fast, like 3GB/s in sequential and 500MB/s in random, but it’s only 120GB. By using it as a cache in a bcache system, once a random read is performed, the data will be copied from HDD to SSD and if the data is requested again the random read will happen from SSD instead of HDD.
Thus, using it to play modern gaming is actually do able. Game that requires fast random read, like Baldur’s Gate 3 and Starfield.
As a lot of people in my og post mentioned, random is more important that sequential. Bcache by default disable sequential cache so you wont fill you cache to fast if a big data is being read, like watching movie, copying video, etc. That’s where Raid0 comes to the rescue. Having Raid0 with 2 drives basically double my sequential read and having 3 triples it.