Yeah, that's a good outline for a Socialist Worker editorial at any point in the last 50 years, but it isn't really true.
The top 1% of income tax payers pay around a 25% of all income tax.
The bottom half of all income tax payers pay 10%.
https://ifs.org.uk/publications/9178
And rightly so, may I add.
I would probably rather they increased income tax than national insurance, but something had to be done.