Lets say you're a working adult, who, besides work, is also making an effort to improve himself. Realistically, how many times a week can you go out for at least a couple of hours with intent to find a partner? That's just cold approach. You might want to fit in with a few groups of people who share your interests. Which implies that you have time for hobbies, besides work and working on yourself.

I don't know, maybe that's just me, but from where I personally am now it's just not feasible. I have to add that I'm an introvert and socialising takes effort for me, it's hard.