Will using subdomain parameters cost more in hosting?

So I'm wand to use subdomain parameters, but keep reading it costs more money in hosting on sites that talk about SEO. Is that true with Laravel?

ex:

Route::domain('{account}.myapp.com')->group(function () {
    Route::get('user/{id}', function ($account, $id) {
        //
    });
});

I essentially want each user to have their own subdomain. Is this viable without a change in costs?