Can't speak for Japan, but the tech salaries in the big cities in Australia and Canada are far more competitive than those in Europe.
The European tech industry is an absolute joke overall, and I say this as a European. It would take an utterly massive overhaul to correct without relying on outright Chinese-style protectionism, and as more companies move remote and snatch top talent in timezone-friendly countries, time is running out faster than ever.
Good luck to European leaders in responding to the question of "Why would I, as a European in Europe, work for a European 'tech' company for terrible pay, when I can work for a US or Canadian tech company remotely for far better pay, on stronger teams, while retaining the same benefits of living in Europe?".