does anyone actually succeed at poker with completely flat strategy.

Tried running super flat lines in low stakes cash a few times, just hitting the same open size, cbetting similar percentages no matter what. I'll be honest, it felt like I was a robot and lost out on value both ways. Either left money on the table or leaked chips by ignoring texture and player tendencies.

I get the idea of reducing variance and keeping things simple, but is anyone actually pulling consistent profits long-term just sticking to a totally flat approach? Or does there always come a point where you need to switch it up? Curious if I'm missing something in the math, or if that's just not a winning way anymore.