Finance is a larger sector, but largely exists to support tech. If tech disappeared, as suggested in the earlier comment, the USA's finance sector would soon diminish to near-nothing and might even totally collapse under the weight of that loss.
For a more relatable example, it's kind of like how agriculture manufacturing (machinery, fertilizer, etc) is a larger sector of the economy than agriculture itself. All well and good when everything is functioning, but if agriculture collapsed, it becomes pretty obvious that said manufacturing would go down with it. It is no help that it is a larger sector.
In modern economies supporting sectors will almost always be larger than the "core" industries they support.
For a more relatable example, it's kind of like how agriculture manufacturing (machinery, fertilizer, etc) is a larger sector of the economy than agriculture itself. All well and good when everything is functioning, but if agriculture collapsed, it becomes pretty obvious that said manufacturing would go down with it. It is no help that it is a larger sector.
In modern economies supporting sectors will almost always be larger than the "core" industries they support.