There is no universally right answer here. It comes down to how much you value a factory warranty and the latest technology versus how much you dislike losing money to depreciation.
The depreciation reality
A new car loses value fastest in its first two to three years. That loss is real money, and it is usually the single biggest cost of owning a new car — bigger than fuel, servicing and insurance combined. Buying a car that is a few years old means somebody else has already absorbed that hit.
Why new still makes sense
You get the full manufacturer's warranty, the newest safety systems, and the exact colour and specification you want. Nobody else has abused it. Many brands offer capped-price servicing, which makes running costs predictable. And if you finance, new car rates are often lower.
Why used often wins
Your money goes further. The same budget might get you a base-model new car or a much better equipped used one with more space, more features and a stronger engine. Insurance is usually cheaper too, and if you are hard on cars, the first stone chip hurts a lot less.
The middle ground
Demonstrator cars, ex-fleet vehicles and cars that are one to three years old are often the sweet spot. The steepest depreciation has already happened, but there is usually a balance of factory warranty remaining and the car is still modern. Look for these before assuming you must choose one extreme or the other.
Things people forget to compare
Run the numbers on the whole cost, not the sticker price: insurance premiums, registration, expected fuel use, service intervals and the price of tyres. A cheap prestige car with expensive tyres and short service intervals can cost more to run than a dearer mainstream one.
A simple way to decide
If you keep cars for a long time, buying new and holding it spreads the depreciation over many years and can work out well. If you change cars every few years, buying used almost always leaves you better off.