Let me tell you a story. I am a linux kernel level developer. Even better, I have implemented multiple windows drivers in my life. And I have tried to implement application level firewall for linux as after 20 years there is still none around (I have abandoned the work as kernel was protected against my method). Proficient in C/C++/Rust/Go/Java/Python/Assembly/... or to rather say it in anything in Tiobe, even Prolog.
I have a nice job at my country at 2250 euros / month (which is twice the average salary) and I was asked to work for some company where I would get around 3000 euros/month.
And now it gets interesting. On interview, they will ask me various questions about my work that should theoretically be memorized by anyone comming from the school education. I have 25 years of development behind me and I dont have the "stack" to remember everything. And I am already decided to give them "fuck off" once they start with the theory.
On other side, I have a child from previous marriage and I will not leave the country for the sake of the team. Child development is more important to me.
So, I am over-competent engineer, bullied by idiotic recruiting, fixed in the position that I have, unable to relocate due to life circumstances. And now "moving to London" is a thing. Yeah right.