Everyone buys different things. That is why you use a basket of goods. Having benefits or wages linked to chrcoluks personal inflation rate makes no sense for anyone. The figures are all out there, its hardly a conspiracy to hide them.
Growing your own food is way more expensive than buying cheapo veg from supermarkets as well.
You're also missing the compounded effect. It may be 3.5% now, but that comes ontop of recent rises meaning CPI and RPI have seen rapid rises in just a few years. E.g since 2020 RPI is up 40% and CPI is up about 28%. So yes, inflation can be 3% now but things are 40% more expensive, as an average than 5 years ago.