I started playing osu! in October of 2021, alongside *cough* (goat). I really never switched to using z/x to tap instead of m1, I also stopped playing as much after that first month, so I had no real way of improving by just playing every once in a while.
Ever since November/December 2023 when I bought a mouse (check setup part) I decided to grind the game a little bit more, my tapping on mouse really improved as well as my finger control on keyboard (to clear this out, i tapped mostly with m1, bursted with m1 and k2, and streamed with k1 and k2)
My most noticable achivements while still maining m1 were: -143 pp 186pp (i was trying to fix it) on Last Goodbye (200pp choke ig). -6 star A rank on Sunglow(ik, typical). -Pass on Bluenation (one of my favorite scores and passes so far). -7 star pass on Gekka*Midare Botan (loved, medal is a cheesy map, doesn't matter).
On late March 2024 I decided to try and switch to keyboard again, this time while learning full alt. Alting fit me so much better than singletapping, no idea why, it's just how they say "you dont choose the playstyle, the playstyle chooses you". I'm not very good yet but my acc is way better in low SR maps compared to when I played them on mouse a year or two ago, so hey, futures looking bright at least.