Comment by aquafox

Most people don't appreciate linear regression. 1) All common statistical tests are linear models: https://lindeloev.github.io/tests-as-linear/ 2) Linear models are linear in the parameters, not the response! E.g. y = a*sin(x)+bx^2 is a linear model. 3) By choosing an appropriate spline basis, many non-linear relationships between the predictors and the response can be modelled by linear models. 4) And if that flexibility isn't enough, by virtue of the Taylor Theorem, linear relations are often a good approximation of non-linear ones.