I feel like the more serious about yourself you are, the better the outcome. Chances are you're a lot more normal than most people on those sites.
Yeah, you gotta wade through the crazies sometimes. I had women with grown up children message me. I just wasn't into that. If I'm more attracted to your adult daughter than you, it's probably not going to work out.
Also there are a surprising amount of women out there who are in their mid to late 20s and have NO JOB. That's just weird.
I'm old, but not that old.
However, don't be rude and don't be too quick to ignore women who message you. There are a lot of women who have more to them than their profile pics.
My fiance actually messaged me because she thought I was cute and I seemed like a nice guy. We started talking and it worked out great. She was really shy on the first date but it went great after that.
You have to really know what you are looking for. You can message a bunch of 24 year old hotties, but chances are you have nothing in common with them even if they are attracted to you. My fiance is a bit younger than I am but she's mature and we have a lot in common.