Unstoppable Domains ONLY allows you to register subdomains on their existing TLDs THEY have chosen for you. This is a centralized approach, as they run the TLDs, and subsequently have control of all subdomains under their umbrella.
DecentraWeb allows you to register ANY TLD that isn't already an existing ICANN TLD (can't register .com, .net, .org, etc).
ENS (Ethereum Name System) currently only allows for .eth subdomains, so much like Unstoppable Domains, they are somewhat centralized with this approach. Furthermore, ENS domains are controlled by a multisig wallet, so technically if they wanted to they could censor or take away subdomains created, or even change them.
The closest competitor to us would be Handshake, and the Handshake protocol. However we feel their implementation is flawed on many fronts. First off, they run their own PoW blockchain, based on Bitcoin. This is problematic, as if you are trying to rewrite one of the base layers of the internet and most important protocols (DNS), you should ensure you're on the most decentralized and secure blockchain around. The fact that Handshake runs its own chain, and one that runs a common SHA256 hashing algorithm, means it is subject to a 51% attack since there isn't much hashing power associated with the chain. We feel something as critical as DNS should not be subject to these types of attacks. Furthermore, being a smaller chain means its subject to potential downtime or other issues. Think about Solana with its recent 20 hour downtime. Something as critical as DNS CANNOT have ANY downtime!
Furthermore, to register a domain on Handshake, you need to go through a bi-weekly auction process. We also feel this is a flawed approach, as not only do you need to potentially wait 2 weeks to get a domain you requested, but someone can outbid you for a simple name you want! We want the process to register domains be open, and similar to the current ICANN process where you can register a domain name instantly if it is available (instant gratification). Imagine being a developer or company and having to wait 2 weeks to secure your domain, and then potentially not even being able to register it due to a bidding process?
DecentraWeb has taken all of this into account and has chosen to run on the Ethereum blockchain to allow its users to register ANY open TLD they can find INSTANTLY!