I don’t think kids are the biggest barrier to enjoying your hobbies. They’re not latched at the tit 24/7 for decades. I think the bigger issue is people have unrealistic work loads/hours, aren’t paid enough, and have lost a lot of the support that used to exist.
Sure, when my kids were small I had a lot less free time, but I still had fun doing childish things. As they got older we ended up trying a lot of things I would not have attempted if it weren’t for them, especially outdoor sports. Now they’re both a bit older and more independent, I have more time to do my own thing. I work from home a few days a week and use that time to go to the gym. On weekends my wife and I take turns so I can go birdwatching - sometimes I take them with me. I’m about to start volunteering at a wildlife rescue in the coming weeks because I have more time on my hands. In a few more years they’ll be even more independent and probably less interested in hanging out with us as much, meaning even more free time.
I can understand having kids doesn’t appeal to everyone, and I don’t think people who don’t want kids should be berated into having them. I also recognise all of this is only possible because I have an extremely flexible work schedule and my wife and I earn a decent living. But to say that having kids is the reason people can’t enjoy their hobbies anymore is disingenuous at best.
I think the above point of the study is key. If you are already facing significant challenges in life (economic, psychological, physical, etc), adding kids is not going to make it any easier, and might make things worse. I know it’s anecdotal but I’m personally pretty satisfied with my life, and that’s continued to grow alongside my kids. But as I mentioned in my previous comment, I have the resources and support I need to make that happen. I also live in a country that provides a lot more support to families than somewhere like the US. Not going to say having kids is all muffins, puppies, and unicorn farts all the time. But it’s been fulfilling to me, and if I had to go back and do it all again with my kids, I absolutely would.