A hybrid toe strap gives you the option to wear it two ways: pulled down over the toe box like a cap strap, or straight down over the top of your foot like a traditional strap. It's basically two strap styles in one, so you can switch things up based on what feels best.
This design makes the most sense if you're unsure which style you'll prefer or if you share bindings with someone who likes a different setup. It's also handy if you switch between boots that fit differently—some boots just mesh better with one position than the other.
The tradeoff is that hybrid straps are slightly more complex, with more moving parts and adjustment points. They work great, but they're not necessarily "better" than a dedicated cap strap if you already know you like that feel. Most riders end up picking one position and sticking with it anyway. If you're experienced and happy with cap straps (the modern standard), there's no real need to switch. But if you want flexibility, hybrids deliver exactly that.