I felt this for the past 3 years. I moved back to the US from abroad, and I feel in the US not many people are serious. I am about to turn 34, no kids yet, but hoping that changes in the next 1-3 years.
As a woman, I had no trouble meeting people (literally I probably matched with thousands and had a few hundred first meetings), but getting to a third date was hard most of the time, as many people on online dating will break things off/ghost if not getting laid before date 4, but I tend to not get physical at all and just kick back to see how genuinely interested a guy is in me.
Finally, I met someone recently, and omg, it was a slow start. First, we began talking in August. We planned to meet in September, but then I got Covid. After I got better, we finally met. I told him before we met that I only date with intention, and he seemed glad for that. I didn't know what to think of him for the first FEW dates, but he kindly paid for the dates, and let me choose places. I never chose anywhere pricey, but I tried interesting spots (there was a Russian restaurant in the area we tried, for example). I was pretty emotionally closed off after so many failed dates before him and I wasn't vulnerable or physical. He still thought I was interesting even though I had a bit of a wall up. He must have seen me nearly ten times in a 5 to 6 week span before I started to relax a bit. I got used to seeing his face and hearing his voice and our little routine of dates after work/on weekends. Finally, I decided to let him come over, and I made dinner. After a few more dates and a few more visits, he asked me to be his girlfriend. Now, his lease ends before mine in March, so he will move to my apartment. He likes gaming, and he sometimes brings his PS5 over and lets me play, even though I'm not good at anything newer than PS2 era. We also play games together, go wander parks, or help each other with things. I'm always washing clothes he forgets here, I took care of him when he was sick already, and we fixed my car together once. (I'm always on a budget and always doing minor repairs myself.) These tasks seem mundane, but I feel us building a bond, and I enjoy just being around him now, even if we are doing nothing in particular.
He's told me before that dating online is a different game for men, and that he was only getting one match every few months, and that they never led to anything. I admit he is only 165cm tall (but I'm 160cm myself) and has a stockier build (though he's very muscular now, he goes to the gym 5-6 mornings per week), and he also drives an even older car than me (mine is 20 years old), and he doesn't make 6 figures, but I think modern daters are too unrealistic. Just being a non-obese male age 25-45 who is at least his height and makes at least 60k a year puts him in the top 4.5% of men nationally. (And America is rich, so globally he's a top 1%er lol) Then, add his personality and the little things I like about him... he's a catch. I think we will work hard for each other.
I really think both partners have to have the right mindset and understand what the real world is like (not social media-- I'm on reddit, but no IG, no Tiktok, etc., and he's similar with social media). I work both a full time job and a part time job as a professional with an advanced degree, but I make time for him as much as I can. I've been living independently for nearly 16 years, and I'd happily scale my work back for marriage and kids with this person if things go well.
TLDR; you will have to play the long game and find someone serious, but it's going to be hard. Telling my story so you know what it might look like. I was scared to be vulnerable with him at first, so it probably seemed at first like I was in it for the free lunch, but that's not the case. I eventually took a risk for someone who was meeting me consistently despite me being stoic and not even flirting for several dates, and now I am coupled with them. Slow can be a sign of disinterest, but it isn't always.