No, not by a long shot. Remember how much time it took for an elaborate Flash animation to load? Sometimes you had to wait for more than a minute before anything even rendered on the page.
And Java applets.. were a joke. A Frankenstein approach to embedding applications in the browser.
By contrast, Wasm IS Javascript, even if the source code might be from another language, it's a target for compilation. It will only be able to do whatever the browser allows it to do, ie access Web APIs, work with the DOM or just do computations that don't output anything UI-wise.
This is not the return of badly executed and badly thought-out plugins, this is "native applications in the browser" done right.