I don't find it stressful really, because I'm happy to be single. So it's not a thing I *need* to get right or worry about. Especially online dating. I set up a profile and let it sit there or play around on the site, and if a fish bites, it bites, and we go from there. If not, no big deal.
I do hear of a lot of people stressing out when they have sent someone a message and they aren't getting a reply. And how it is considered rude to not reply, even to say "sorry not interested". To me this indicates the whole thing is being taken too seriously. Personally, I'll send a message then basically forget that I did. If they don't reply, I won't notice. If they do, great! (Unless they reply to say they are not interested. That's kind of annoying, I didn't need to know that. But that almost never happens, it's usually just no reply.) I mean sure, there are some people who seem really interesting and I will remember them and hope I get a reply, but that's the extent of it - vague hope. I don't think it can be anything but detrimental to be any more serious about it than that.
In the real world, well, it is disappointing that I suck at meeting people, but it's not "stressful". Now if I needed a job and was struggling to find one, yes, that is stressful. That's a thing I need, and I need to impress potential employers, so it's more serious. But then again, I've done just as well in job hunting when I've decided not to worry about it much and just be myself. So again, taking it too seriously has not been useful.
I guess I'm lucky that I enjoy dating for its own sake. It's a shame that so many people don't actually enjoy the process, and are only interested in the result. Because yes, a lot of time and effort may need to be put into the process. I mostly enjoy doing this, so I suppose that already puts me in a better position.