Actually, you're missing the bigger picture of how Cardano approaches scalability. It's not just about relying on layer 2; it's about designing a holistic system that mimics natural ecologies where each component has a specialized role.
First off, Cardano is actively enhancing its base layer with upgrades like Ouroboros Leios, which aims to significantly boost transaction throughput directly on the main chain. This is about making the heart of Cardano pump more efficiently without needing to outsource every function.
But let's talk about layer 2 like Hydra. The point isn't that Cardano 'has to rely' on these solutions; it's that Cardano is designing a system where different layers serve different purposes, much like organs in a body. Hydra isn't a workaround for scaling; it's an evolution where specialized 'heads' can handle specific types of transactions or operations, leaving the main chain to focus on what it does best - providing a secure, decentralized ledger.
Think of it this way: in nature, you wouldn't expect the heart to do the job of the liver or the lungs. Each organ specializes, and together they make the system work efficiently. Similarly, Cardano's approach isn't about a single layer trying to do everything; it's about interoperability and specialization.
Layer 2 solutions like Hydra, Mithril, or partner chains are not signs of limitations but of foresight (written from the beginning), allowing for tailored solutions for different use cases while maintaining the integrity and security of the main chain. It's not about being 'stuck' with layer 2; it's about the design of more robust, scalable, and adaptable network.