there would always be an alternative to living in the UK - the other country.
Sucks if the other country also makes it hard to stay.
I don’t know how well anyone can support themselves on £18,600
If so, then that's an admission that every British citizen should have the opportunity to earn more - enough to live on.
I suppose it's not an unpopular opinion here on Lemmy, but probably is in a lot of the UK: IMHO spouse and children of a citizen should always be admitted into the country and treated without prejudice. If supporting someone in poverty is a drain on the nation, let it be same for spouse as for born citizen. If we should help people become productive workers: same for spouse as home born. If... etc
I know people exploit that with fake marriage and other ways, but, like many good things we do in the UK, the fact some exploit them doesn't make them a bad thing, or worse than the alternative.