As of June 2025, the UK had only a shade over 100,000 people receiving asylum support, with about 70k cases awaiting a decision. So not millions.
And to answer your question - it's not supposed to help us, that's not primary reason we accept asylum claims. This is the part of the issue that's deliberately muddied - the grouping of immigrants, illegal immigrants, asylum seekers etc as one. They're not.
We allow controlled, legal migration because it benefits us. Asylum seekers and people here illegally make up such a small percentage of overall immigration, it's laughable.
The biggest problem with the asylum system (internally at least) is that it's simply not fit for purpose. Underfunded, understaffed, under-resourced. It takes too long to process people, the systems for housing, monitoring and supporting them are held together with sellotape, and the process for removing people with no right to be here is complex beyond belief.
Many governments have known this, but non want to be seen spending the vast, vast amount of money necessary to fix it 'on immigrants'.
So we're left with mentally ill people who aren't getting treatment. Criminals who aren't being monitored. Traumatised people left unsupported. Regular people driven to irregular acts through poverty or desperation.
The UK does have issues with immigration, abuse of the benefits system, housing, the NHS...but make no mistake, the people who blame all of the above on 'illegals', benefit fraudsters/blaggers or whoever else the boogeyman of the week is, are doing so because they are very easy answers to very complex questions, and that's all some people are willing or able to listen to.
NHS overstretched? "Stop letting people in". Sounds logical, gives angry, frustrated people someone to blame, but utterly fails to address any of the systematic and practical issues at the root of the problem.