I think car performance modifications like replacing an average car engine with a very powerful engine in a car is usually not worth it for most drivers who are not interested in cars as a hobby, don't tow a lot of heavy things like a boat or trailer, and mostly drive their car on public roads where there are speed limits, and other road laws which they need to follow to keep the roads safer for its users.
But, car performance modifications can be useful in rare occasions if a driver suddenly need to drive faster to escape being crushed from a falling rocks from the side of a mountain, and out of control car which is driving very quickly toward other cars because a driver suddenly hit the gas pedal very hard where the car goes too fast.
If you have a family or not so 'much' rich it is not worth it. But if you have some cash to burn on things that you can only enjoy on very rare occasions then it is worth it.
I agree buying car performance modification parts like a more powerful engine is not worth it if you are poor, and need your money to support your family, or buy food to feed yourself. But, can be worth it if you have more money, and enjoy more powerful cars.
I think car performance modifications like installing a more powerful engine can be worth it if the car owner need to replace a broken car part like an engine, and they decide to spend slightly more money on more powerful car engine which maybe made with better metal, and have a longer warranty than cheap replacement car engines which don't always have a longer 5 year or longer warranty.
Sometimes, buyers may save money buying a more powerful used/refurbished car engine from eBay instead of the same type of car engine which came with their car from a car dealer which may sell official car parts for more expensive prices to earn more money.
Don't frame it as a need. It's not about a need at all. No one needs more than 4 cylinders in a car or steak dinners or fancy jewellery or videogames or etc...
It's a want.
From there, if they want to spend their hard earned money on it? Let them. It's their money so who cares what they do with it?
Sometimes it is worth it depending on the vehicle.
A relative of mine installed a chip in the engine to boost power on their SUV which they used for towing. This allows them to more easily tow things without worrying about loss of speed on hills. Now it'd never put it on the same level as a truck (since there's still no replacement for displacement...) but it's far better than it was.
Though not all performance mods are about getting more power/speed. Some people install chips to allow them to control exactly how much fuel is burned. This way they can run leaner in the city and therefore saves them money on fuel. Similarly high quality/properly inflated tires can be a performance enhancer since the rubber rolls better and thusly reduces strain on the engine (less to overcome to make it move).
Tonneau covers on trucks are another, unlikely, performance mod. They cover the truck bed and cause air to flow over the bed, not cycling in it, and thus reduce drag and increase fuel mileage.
Well, honestly it depends on our opinions I suppose. The colors, extras and everything else...it depends. My mom has this sentiment of having me and my sister's names on our car.
It's kinda expensive...but even if those names made away, she would immediately get them done again xD