Memory cards do fail. It is as simple as that. But they do so very seldom, in fact very, very seldom. But it can happen, and therefore, with so many memory cards out there, it will happen.
I have 5 cameras, shoot in the vicinity of 30.000 pictures a year (RAW format), and have never had a memory card fail on me. But you cannot use the past to predict what will happen in the future – the probability of a card failing on you is bigger than zero. It is as simple as that. It will happen, maybe not to you this year, but it will happen to someone this year.
So do you need dual card slots? It comes down to your risk profile. Most wedding or event photographers turn pale thinking about the conversation they will have with the client, when it turns out that some or all the pictures are lost. So many pros will be very risk adverse and demand dual card slots. And for a good reason: resilience is the cure.
For happy enthusiasts the situation may be a bit different. It is not necessarily a catastrophe if your pictures are lost, and that in combination with the paper thin likelihood of a card failure, leads many to settle for a camera with only one card slot. And the camera producers know this, and save some money making most camera models with only one card slot. And you can make your own version of resilience, and bring two 1-card-slot cameras where you alter between the two throughout the day – not as resilient as two cameras with two cards slots, but a lot better than only one 1-card-slot camera.
So my answer to the question is as annoying as when you ask your bank advisor for investment advice: the first thing they ask for is your risk profile. But it is really what it comes down to. With this reservation, my answer without knowing your risk profile is yes if you are a pro and probably not if you are an enthusiast.
Further, to preserve your data, you probably do backup the pictures on your PC to some alternate form of storage. But remember that it is not only the data that needs duplication to make a good backup, it is also the location. I once worked in a company that carefully did backup of their servers every night. Only to find that thieves one night ran with both the servers and the backup drives. So make sure that your backups are at a different location than the original, to counter both theft and fire. Cloud based backup solutions fulfill these requirements, so please factor this in next time you are to choose between a physical backup drive or a cloud based ditto.
Thank you for reading this far! Comments and questions more than welcome!
