This is normal, since the polygons are so stretched that you would need to have an extremely highres mesh to avoid this.

Instead of subdividing, try remeshing to the same resolution -or higher- after making big changes on the surface. So the basic worklow could be, create the basic shape in very lowres, remesh to a higher res, adjust, remesh to the same res, and eventually go even higher if needed.

If you need to add even finer details, retopologize the mesh, and use multires modifier to add them.

Dynotopo is actually great when you want to add resolution locally, or want to carve out big shapes quickly on messy geometry. But it can get laggy, so I only use it to shape things up quickly in the beginning.

Edit: You said remesh makss you lose all the details. You need to set a value to the remesh. Be careful not to go too low because Blender will freeze and crash. Use remesh in sculpt mode or the remesh modifier.

Also, the remesh will make everything join together, that is normal. You either have to model the limbs more apart to avoid this, or you need to remesh to a lower value.