Stationary bikes never feel natural, because they're rigidly upright, with no side-to-side play. In real cycling the bike is often wavering off-center as your legs pump.
An Austrian startup called Curveplate aims to provide a more realistic feel with their eponymous product. Two curved plates that serve as rockers can be mounted beneath your stationary bike, allowing you to tilt it from side to side as you pedal.
"This means that left-right movements of the entire exercise bike when pedaling not only make riding more comfortable, but also that avid athletes can experience actual cornering of up to 9 degrees - without tipping over. This increases the joy of training through more variety, improves coordination and balance and trains a large number of additional muscle groups - especially in the torso, back, shoulder and arm areas."
I wondered what would happen if you exceeded the range of the rockers. The company's FAQ states, with characteristic Teutonic bluntness, "No you can't tip. The use of the Curveplates has been intensively tested for stability. An official test procedure was successfully completed - according to DIN EN ISO 20957-10:2018, 5.6/6.6."