How is believing that being single through the entirety of your 20s is a good thing anything different than a lie?

Basically if you Google single in 20s there are dozens of videos saying that your 20s being single is about finding yourself. Now obviously there is a niche for this but I am sure some believe it.

I am 29 and spend my 20s single and I feel not only like I haven't found myself but that I am way less experienced than people who were in a relationship in their 20s some of which recently married as they learned how to cohabitate with someone else while I being a single child with parents having to travel overseas spent a lot of my teens by myself and then moved in another city.

Basically I build a perfect life for 1 person but I feel like I lost the opportunity to learn the valuable skill of living with someone else.

So maybe finding yourself and optimising your life in your 20s is actually a bad thing and makes it harder afterwards.