About ten years ago I (M40) realized I wasn’t cut out for long-term serious relationships. I’d been in several, including a couple where my girlfriend and I were living together, but for whatever reason they didn’t work out and I discovered I was much happier living alone and doing my own thing. But that didn’t stop me from dating, what I discovered is that if I was completely up front and honest with women that I never wanted to get married or live together that they respected the honesty (informed consent and all). It turns out there are plenty of people who are in between serious relationships and just want something uncomplicated and fun for a few months, and there are plenty of people like me who prefer living alone and doing their own thing but still like going on dates now and then.
It seems like most posts about dating and relationships are people who are frustrated that their relationship isn’t working out. Maybe they just haven’t found the right kind of relationship. My current situation is ideal because when women know exactly what they can expect from me and know they won’t be led on, they’re happy to spend time with me without me having to make grand gestures or sweeping promises. They can date me for as long as they like and move on if they want and everybody wins, no one gets frustrated or annoyed or disillusioned with the other.
TL;DR: Casual relationships are still relationships, and some of mine have lasted multiple years and have been way more fulfilling than traditional long-term relationships.