I wouldn’t say the websites are a waste of time, BUT some of the shadchanim there, like shadchanim in other venues, sometimes try to redt shidduchim that for specific reasons are really not shayach to the person, because they just KNOW they know better than the client who has signed up for the site.
I personally know at least ONE shadchan on a well-known site, and in my humble opinion she should not be matching up sox, much less actual people. I mean no disrespect to her, but true is true. So how on earth did she ever get to become a shadchan? I think there should be a better screening process for them, so this would not happen. This does not minimize the massive efforts of shadhchanim who are truly dedicated to helping couples meet and marry. They deserve all the kudos we can give.