Paint peels and stain fades. At least this applied to oil base stains. Some acrylic stains, if applied thickly, can also peel but peeling stain feels different than paint.
Yes, if your house has paint on it now then it will have to have paint in the future. This is a bummer as cedar siding is best stained not painted. Your painter will know for sure when pressure washing, old stain usually comes off easily while paint can fight to the bitter end.