some of the compute workload still needs to be on a backend because of security concerns.
if you offload too much stuff on a client-side, then any hacker can mess with it and break your system.
for example you can get angular debugger extension for chrome and mess with any online shop that uses this system to "adjust prices" for your cart during checkout
This is only a problem for online services, multiplayer games etc. These shouldn't trust client-provided data, including data that comes from WASM. But there are countless applications that can be entirely local, with no need to interact with any sort of "cloud" services. WASM can potentially be quite helpful there
for example you can get angular debugger extension for chrome and mess with any online shop that uses this system to "adjust prices" for your cart during checkout