In hospitality, an empty table or an unsold room is money that never comes back. Someone books for Saturday, does not show up, and by then you cannot fill the table. And when shifts, purchases and the till all run separately, the night goes on making the paperwork add up.
And what already exists has its price. Booking sites keep part of every booking, software charges you every month, and your customers sit on someone else's platform. Sometimes it is worth it and sometimes it is not. It is worth looking at before building anything, and if it does not pay off for you, we will tell you.