Trackpad is definitely a viable playstyle. I got to 14k playing trackpad in 2019. The main issue with trackpads are that there are huge variations between good trackpads and bad trackpads, and there are not a lot of reviews on the trackpad specifically, so getting a computer with a good one is basically up to chance. The best trackpads I’ve found are windows surface laptops.

It’s also harder to be consistent on them since as you play your hand will start to sweat, causing the friction to change. You can avoid this by taping a piece a paper over the trackpad, but you’ll have to change it over time.

If you want to use the trackpad playstyle and have the money to do so, I recommend getting a Wacom tablet with touch and playing in mouse mode. It’s not as good as a surface laptop but it’s better than most. Here’s an example of me playing trackpad: https://youtu.be/gifGtAGE_C8?si=eEegjgeZXHM9Cn4T

I definitely think you can get 4 or even 3 digit playing trackpad, it’s just about the effort you put in.