Yeah, the stories don't have much substance, but then again most action anime/manga don't either on that front. It usually comes from the characters. Which Jojo's does do well as it goes on for the most part. Regardless, the series is more of a 'fun' ride, than a serious contemplative one anyway. I am sure you realize this already.I get a kick out of the poses, the macho, androgynous designs (mostly from those I've seen of future parts), music references... there's a lot to love there.
This is very much style over substance so yea you have to like that to hang with it. In general, I don't pick a side with style or substance, even if the latter is longer lasting, on first view style holds up well. So I don't have a problem here.
I'm not particularly with Stands, yet. I preferred Hamon power lol. There are some enjoyable Jojo fights, what kills it is the amount of them in part 3. Every episode or two we'll come across a stand user.. even though they're literally traveling to a goal it feels like we're not going anywhere. Idk, I was getting a headache from that. I have contemplated skipping straight to Jotaro vs Dio, so then I can start Kira's part. If part 5 is a hit anime, then I'll probably feel more pressure to finish part 3.
I think you need to get further with the stands. I agree that at first, they seem pretty standard for an ability system. However, as the series goes on, the creativity that the author employs with them is far higher than most battle series. Only HxH really rivals it there, maybe OP too. The latter only in the abilities themselves too; the situations he creates are what make them fun.
As for the number of fights, that kinda is the charm of it, but I definitely see why it would burn someone out. Especially, in the first half of part 3, which is easily the least creative section of the longer Jojo parts. If you do go back to it, I would stick with it until the end. There is some decent payoff to hanging in there with the crew.