There are many legal routes to immigration and seeking asylum. People choose to move illegally because they won’t succeed on the legal routes and know that once they’re in the country the chance of them being deported is pretty low.
If you barely speak the language, it's not easy. Unfortunately many countries have made immigration so hard, in an effort to combat it, that they've done the opposite - people immigrate illegally because it has a higher success rate than doing it legally.
If I apply for X, Y, and Z and I'm denied, I'm fucked. But if I just move... And then figure it out later... That might work better.
And that's how we got into this mess. A lot of this anti-immigration legislation actually increases the incentives for illegal immigration.
Yes, that's the part that needs to be fixed.
In all countries there are posh, elite, nice areas, and yet you don't see everybody moving into those areas until there is no standing room. There is a natural equilibrium that is effective.
So overly tough immigration policies actually exacerbate the problem of illegal immigration in this way as well.
I, a software engineer with decades of experience, and now an entrepreneur having a small startup, with funds to live for years without burdening the public purse anywhere, specking virtually native level English, and having previously lived in the US for years, would still have a _very_ hard time immigrating to any western country right now, partly because I'm from the global south (I'm Ghanaian).
If you know of any western country where moving there, even temporarily, is as simple as applying with my information, let me know.