The IPNS make that unique identifier easier to access. Also, different from domains managed by a DNS provider, blockchain domains don’t need to be renewed every year. Once you own it, it’s yours for life.
One of the biggest benefits to blockchain domains is how it aims to combat hacking. With a DNS host, there’s a centralised organisation maintaining and monitoring domains. IPFS blockchain-based domains work a majority consensus model. Ideally, this makes it harder for hackers to get control of your domain.
It’s also worth pointing out that blockchain domains aren’t hosted on a server. They’re stored on public blockchains for transparency. Like found throughout blockchain technology, this system cuts out the need for middle men (domain providers), and creates a direct link with the owner.