That's a lot of rhetoric. Where is this 40+20+13.8 coming from?
Employer NI is 13.8%, but rarely counted as a tax on the worker (crazilly)
Of course plenty of people earning big bucks don't do it via PAYE, just take their money as far lower capital gains, split income amongst multiple people, leave income in businesses for longer, etc.
2017-2018 figures [0] and taxes [1]
Someone on 90%ile 45,500 pre tax, has a cost (including employer NI) of £50,616, and a net wage of £34,322, total tax of 32%
Someone on 95%ile 59,300 pre tax, has a cost (including employer NI) of £66,320, and a net wage of £42,413, total tax of 36%
Someone on 99%ile 116,000 pre tax, has a cost (including employer NI) of £130,845, and a net wage of £72,099, total tax of 45%
I believe Corbyn's income tax proposals were to increase the rate for 80k-150k to 45%. That would only affect the top 2.5% of income tax payers, but the person on the 99%ile above would pay an extra £1800 a year in tax. Their tax rate would change from 45% to 46%, hardly an earth shattering change.
That £1800 a year extra is about what the tories took off single mothers earning £60k when they introduced the child tax [2]
[0] https://www.gov.uk/government/statistics/percentile-points-f...
[1] https://listentotaxman.com/
[2] high income child benefit tax charge".