There are two rules for wire sizing, one for the utility company and one for the rest of us.
Utility companies are not bound by the National Electrical Code for the service drop to your house. Although you do have a 200amp service, you are likely to use only a portion of it at any particular time. Also, utility company with look at the transformer size feeding the houses and mountains of historical data when sizing service conductors/service sizes.
We have a single 37.5 kVA pole mounted transformer feeding four house (including my shop that has a separate 200amp service). Considering the transformer only outputs 156 amps and it has been there for forty years, shows that the power company knows how to size the services based on real world loads and not nameplate loads. Not everything is going to be running at one time, and if you do get a spike it is for a short duration. So they don't figure your actual loads will need more than they pulled to your house. If they are wrong and the extra heating of the conductors cause the insulation to break down, then they will fix/adjust it at that time. But 99% of the time they end up being correct.
It is not uncommon in the business/commercial world for power companies to only provide transformers/conductors at half the capacity of the rated service entrance equipment. In industrial applications where you can prove beyond a shadow of a doubt that your customer needs the full rated capacity of the service equipment, they will still only generally give you 80% of what you ask for. And again they are generally correct. Rob