I played almost all 4* maps and yes, you just discovered that the 4* range has lots of variety, different mapping styles and some of them actually require (a "unique") skill.
Sadly most people skip those maps and miss out on lots of fun. I strongly recommend you to play those maps, they might not be worth pp, but they are the most satisfying maps to play and once you are good easy top 50 nomod scores.
Just to name a few of my favorites that ain't generic:
https://osu.ppy.sh/s/223092 (the best map in this game, play it without hitsounds, it's mapped on point lol)
https://osu.ppy.sh/b/1104317&m=0 (fun fun fun)
https://osu.ppy.sh/s/258193 (od9+really spaced triples+128bpm streams, worth nothing for the effort; only a handful of people actually FCd it)
There are hundreds of maps that are really unique and insanely hard in the 4* range, just naming those 3 because they are really fun. There are also not so "cancerous" maps that are hard for their star rating, but sadly they don't get the attention they deserve.
PS: If you can play almost all 4* maps consistently you will have an easier time closing the gap to 5* maps, but that's another story. Just trying to motivate you to not skip maps :3