Immigration restriction based on skills should be regarded equally sceptically as restrictions according to race.
Restrictions based on skills assume that The UK is no more than a large company importing skills and exporting goods and services. This triumph of unrestricted capitalism objectifies us all and values nothing but profit.
I have several friends who lose out to new immigrants when looking for work due to their age.
Capital and labour markets are now global but laws to protect workers and provide basic healthcare operate only at national level. This is why our governments constantly snip away at pensions and healthcare to reduce the UK government’s operational expenditure to that of our “competitors”.