The difference between a good review and a great one is usually timing. A check-in reminder that lands the morning of arrival. A house manual that arrives before it is needed rather than after. A review request sent while the stay is still fresh.
Doing this by hand means remembering every guest at every stage, and it is the first thing to slip when you get busy. Automating it means it happens the same way every time, whether you have one booking that week or ten.
The part most owners overlook is what happens afterwards. A past guest who books directly costs you no commission, and a well-timed follow-up is the cheapest booking you will ever make.