A dental crown is like a helmet that goes over the tooth and protects the underlying tooth structure - providing a predictable long term restoration for a weakened tooth.
You are free to choose any restoration of your choice. It is important to consider that patch treatment often ends up costing more in the long run. Research shows that in the majority of cases where a filling has been placed as a 'patch' job instead of a crown, the cost of replacing the fillings a few times over the next few years exceeds the actual cost of placing a crown in the first place. Factor in the extra time spent in the surgery and local anaesthetic endured for the extra visits and it makes more sense to fix the tooth once, instead of 3-4 times thus saving both time and money.