It's a bit exaggerated due to other factors (see below). It would be great to see a controlled study where some randomized participants were encouraged to switch to cycling to see those results.
"Due to the limitations of the SLS, we were unable to adjust for some potential confounders, such as income or body mass index at baseline, we were not able to account for time-varying confounding and excluded individuals with missing covariate data. Additionally, active commuting may be associated with other forms of physical activity that contribute to total physical activity levels.39 However, we were unable to adjust for other forms of physical activity, another limitation of the dataset used. This may have led to an overestimation of the effect estimates, particularly for cyclist commuters who have been shown to have higher levels of overall physical activity than other commuters.7 Nonetheless, previous research has demonstrated that beneficial associations between active travel and health remained after adjustment for other physical activity.3" https://bmjpublichealth.bmj.com/content/2/1/e001295#:~:text=Due%20to%20the%20limitations,other%20physical%20activity.3
Warning: the poll behind this article has false data because of biased question wording and order. See here for examples: https://lemmy.world/comment/14503824