You need to seal and stain the wood. Depending on the brand that could mean every year or every 2 or 3 years. The wood will rot otherwise. But maintained then p

You need to seal and stain the wood. Depending on the brand that could mean every year or every 2 or 3 years. The wood will rot otherwise. But maintained then pressure treated pine (or outdoor hardwood) will last a long time. You’ve also pointed out the problem with plastic. It fades and if you were to add new plastic it would look off.