This was very much about 'making work pay' and aiming to improve productivity. Important though national insurance tax reductions are to help sole traders and partnerships, they do nothing to help those caught by frozen thresholds or running small limited companies.
Sole traders and partners
With Class 2 national insurance abolished and Class 4 national insurance reduced by 1% from April 2024 but dividend tax unchanged, more businesses may decide to remain as sole traders rather than incorporate or even prefer to disincorporate.
When you add in that the cash basis will become the default way to measure tax profits from April 2024 (for any size sole trader) together with the previously known companies house reforms requiring more company information to be made public, the government clearly wants small businesses to stay as sole traders unless they're large enough to embrace being a limited company in full.