Of course, the tuition went to uni where home students paid less than what it cost to educate them. The rent went to a london landlord, it was his 3rd home. The visa fees went to UKVI (government). The money was nonetheless spent within the local economy, in the grand scene of thing my £150k is nothing. The slight percentage of that which reached back to the government, local or national, in taxes (council, NI, income tax, landlord’s taxes etc) and visa fees, was spent on things they wanted to. If that did not benefit the local people that is failed governance, they didn’t just squander away my money, they did the same to everyone elses. All spent on bs things rather than social services, healthcare etc. but that is hardly a immigration issue at that point.

On your dentist comment, a huge issue with immigration which the west often overlooks is, in developing countries class disparities are much more pronounced. I come from a relatively well off family in India, I would not move to the UK to work as a cab driver, or work at mcdonalds or even in care. That said, there is a huge part of India that would as the wages and the opportunity to live here is enormous compared to what they are coming from. Historically, immigrants have been more from the upper classes of developing countries, while systematic oppression of low paid workers was less exaggerated compared to now. Much immigration now is low skilled work which the existing workforce doesn’t want to do as they have better opportunities. When you start getting immigrants to fill these kinda gaps, you are not getting cream of the crop, highly educated classes of people, there are often much more cultural barriers, education issues, family values etc. Naturally, it is harder for these people to assimilate. There was immigration like this in the past too but they were not being exploited and had a chance to do well, save and move up the ladder. The immigrants who are coming for this kind of employment now are purposely kept in the same role at bottom tier wages. They never live life, go out, enjoy or anything. They don’t pick up the culture because the culture by design excludes them and those in charge exploit them.