WebSQL is deprecated IIRC - the problem with complex databasing like SQL is that users are never meant to be querying directly on it. SQLite has a number of functions that are pointers to your own functions to override/add behavior. If a user could simply query that - poof you're SOL.
Which means to be safe from the host system you have to virtualize the execution somehow - WASM is exactly that. Therefore if you wanted sqlite in a browser, you can simply compile it to wasm.
Which means to be safe from the host system you have to virtualize the execution somehow - WASM is exactly that. Therefore if you wanted sqlite in a browser, you can simply compile it to wasm.