part ... I must admit ... it's a pain in the !
Tbh ... ... I'm still not sure if it IS, in fact, an essential requirement. Reason for me NOW querying it in this instance is because, when my wife and I went to Rome a year past in June, we DID make such arrangements immediately prior to visiting the Italian Embassy ... purely for the sake of complying with the instructions on THEIR Application Form.
Having said that, we'd been to Paris 15 months earlier, and the French Embassy HADN'T insisted on details of travel arrangements and/or accommodation being provided beforehand.