Not all of them. Some are indebted to the smugglers who are lurking and waiting time to demand the "successful" migrants to pay them back.

Also, remember that only a minority of would-be refugees are smuggled into the country. Most of them enter on visas or other legal entries, then apply for refuge, which is what the UK government currently say to do because there are no legal routes to apply for refuge when not already in the UK.

Most that come to the UK aren't genuine

I'm sure you wouldn't make a claim like that without a legitimate source