After my younger son graduated from university he came back home and picked up with the job he had during and after A levels. This job was ok then. Being a sales assistant in a fashion chain was not part of his long term plan, but needs must at the time. This chain was owned by a greedy bugger who also has sports shops and I believe a football club and likes his staff on zero hour contracts. He was expected to work all sorts of unsocial hours, which he complied with, the unsocial hours were often outside the shop's opening hours as stock was delivered late at night and staff could be sorting it till the early hours of the morning sometimes. The last straw for him was working an early morning shift on Christmas Eve something like 7am to 2pm, and an hour after he got home he was asked to come in that same day, working 10pm till 4am Christmas morning to receive stock and arrange it for the sales. He refused, he already had other plans in place, the shop manager texted him along the lines "it may not be much of a job, but you are lucky to have it!" He texted back "you can keep the job I'm resigning" After that he got down to some serious job searching and was a few months out of work and then got two offers in the same week. He now works for a publishing house in London where he is happy. He has told me when a couple of colleagues there were moaning about temporary long hours for a book launch, although not that long I gather, he said to them if you had ever worked on a zero hour contract in a trashy shop which involved at times working till the early hours of the morning, it would put these hours into perspective.
It's not all bad news, I do think some employers like to see University graduates have done menial every day jobs rather than float off on expensive gap years at their parents expense. My son did get that feedback from his present employer.