Every hard drive will fail. Standard hard drives use rotating platers that are driven by moters and spin in bearings that wear out. Solid State Drives use flash memory to store your data, these memory cells wear out making it impossible to read or write data to them.
Every day computer viruses destroy data on countless computers. Some even encrypt your data and demand a ransom to get it back. Reliable backup is the only protection against this type of data loss. Don't let the bad guys win, protect your valuable data.
Your car, the airport, even your home, theives are constantly on the lookout for ways to steal valuable computers. Don't let the theives be the only ones to enjoy your vacation photos, reliable backup can take the sting out of a lost computer, make sure your data won't be just a memory.