Still rocking my Series 5, and ironically with the $2.99/month Apple Care, nothing has ever gone wrong with the watch and the battery life is still holding. My BF on the other hand has really bad battery life on his 5(and he doesn't have Apple Care so go figure). I found this article quite useful, and ended up getting him a Series 8 on Amazon, they had some rock bottom pricing yesterday so it's going to be a great upgrade for him.
I agree with many other posters, the watch is not a "must have" for me. I know I work out and I don't need to track every step and every mile I ride my bike. If I worked in retail and had to lock my phone up before my shift, that might be another story.

I was talking to a friend who has an iPhone and MBA but no watch and he asked me if he should get one. I had a hard time justifying it as a necessity to him.