I did an ancestry one recently, it was rather fun! Can’t compare to 23&me though as haven’t done it. I’m American and as the Americans are very into family history, my family tree back to the 1600s had pretty much already been mapped out for me by other members. I think it uses AI to suggest potential/probable ancestors as you work your way back through time, based on what other people have already added. It was also interesting seeing my genetic breakdown, despite both parents being American I am apparently 80% English. Have fun!