My understanding is Deliveroo riders are provided with lights, front and rear. If they can't be arsed to use them, then...
I was walking last night, and saw a cyclist approaching. He didn't have a front light. As he got closer I realised that he had one, it was just very dim. I called out to let him know - as he was wearing headphones, he stopped to ask what I said. Then I saw that his lights didn't look dim close up, they were just so low powered that they didn't do much good even from a few metres away. I also saw he was a deliveroo driver.
If that's the quality of lights they are giving to their riders, I understand why many don't bother with them.
(It was a well lit street. Maybe they are more visible on a dark street, but as they don't cast much light, the rider wouldn't be able to see much on a dark street)