According to a quick google 180,000 people per year are reported missing.
I’m really very sorry if you are personally affected by this case but in the cold hard facts are missing people can be extremely difficult to locate. Put in perspective that someone could literally be anywhere then it’s unsurprising that missing people don’t draw publicity unless there are concrete clues/evidence pointing to their location. The media won’t give up column inches easily.
You being unaware of her is not an indication of how hard the police are working. Do you routinely check your local news, local police website, missing persons sites in the UK? I bet the information is there but doesn’t register on your radar.