dp
In reality you will often get higher clearances especially if you are already there.
Why might you want a clearance? Well, I have been coming up from Newquay or back for Waterford non airways but VMC above. Often it makes sense to stay in the clear air on top, especially if it means switching on the anti ice, or to avoid being bumped around, even if it is only for a short time.
If you are not instrument rated you definitely don't want to be descending into the cloud for the crossing but to be fair if that were the case ideally maybe you shouldn't have been there in the first place.