Suburbs are unlikely to support everyone walking to the train station unless they were explicitly designed for it. You’d need immense parking lots/garages at the suburban stations (which most transit advocates oppose and are trying to remove), blanket coverage with local bus service (expensive and structurally difficult in a suburb), or to remake the local streets around bicycling. Plopping down a station without a last-few-miles solution doesn’t get you much.

Suburbs (and small towns) can implement local bus circulators for last-mile solutions to connect with central stations.

Local bus service can be helpful for the disabled or in extreme weather conditions, but rarely beats a brisk walk. They usually average under 10mph while in motion; then add 10+ minutes of 0mph waiting.

A 40 minute walk and a 40 minute train ride are both reasonable commutes, but added together are nightmarish. I’ve tried.