In the English Grammar Profile, B2 point 5 in the category of FOCUS is defined as:
‘The thing, fact, point, problem, or reason + is (that)’ for focus.
For example:
The fact is I can’t take any more of your money unless I raise the rates on you.
However, we believe the structure should not be limited to just the article ‘the’. For example:
My point is, you pay the ransom, what, eighty bucks?
Also, note that the structure does not need to be at the front of the sentence:
All right, no bullet catch, whatever,
but the point is a real magician tries to invent something new that other magicians will scratch their heads over.
Here are more examples from google news:
Brisbane TimesThe thing is that any additional money you have sitting directly in your mortgage is not safe for you to access at any time.
Warrnambool StandardThe fact is, high carbon emissions are embedded in New Zealand’s tourism GDP.
Washington PostThe point isn’t that the cognitive test is easy. The point is that Trump keeps bragging about it.
PetaPixelWell, the reason is that this pandemic has had somewhat of an unprecedented impact on many industries.