Source: https://www.awwwards.com/best-webgl-games-best-HTML5-games.html
Content is harder to protect. Web assets and client-side code are delivered to the player's device, making them easier to inspect, extract, or reverse engineer than a conventional native build. Obfuscation can raise the effort required, but it should not be treated as strong protection for sensitive logic or valuable assets.
Loading and storage require a few more layers of production discipline. Large textures, audio files, animations, and 3D assets have to reach the player via the browser, so initial download size and caching strategy directly impact time-to-play. Offline support is possible, but it requires additional architecture and is less simple than shipping a self-contained native package. This is why HTML5 is a great option for compact games, while content-heavy games require much more careful asset budgeting.
The gap is also getting smaller. WebAssembly was introduced partly to improve performance for demanding workloads, while WebGPU provides access to more modern GPU capabilities. These technologies make ambitious browser projects increasingly realistic, but they do not remove the need to choose the platform around the game's actual requirements. For projects approaching console-level rendering, deep hardware integration, or a large technical scope,
full cycle game development around Unity, Unreal, or native technology can still be the more efficient production decision.