WASM is inherently slower than native, but it does very well!
We have some micro-benchmarks here that have some baseline native numbers to compare to: https://pglite.dev/benchmarks
Much of the complexity with WASM in the browser actually comes down to the performance of the underlying VFS for storage. When running in-memory or using the OPFS VFSs both PGlite and the WASM SQLite builds are very performant, absolutely capable of handing the embedded use case.
We have some micro-benchmarks here that have some baseline native numbers to compare to: https://pglite.dev/benchmarks
Much of the complexity with WASM in the browser actually comes down to the performance of the underlying VFS for storage. When running in-memory or using the OPFS VFSs both PGlite and the WASM SQLite builds are very performant, absolutely capable of handing the embedded use case.