Exactly!
Countless times in this forum, we have fielded questions from people who claimed that their meticulously-maintained vehicle was having problems, but upon questioning them, it turned out that their interpretation of well-maintained consisted of changing the oil and washing the car regularly.
I don’t buy used cars, but if I did, I would not even consider one if the current owner couldn’t provide me with a stack of maintenance invoices detailing its maintenance. And, even with good documentation, I would still want to have my own mechanic inspect it prior to purchase, in order to detect incipient problems and rust damage that might not be apparent to the buyer.