2666MHz is spec from Intel, and it is optimal. Just because you can spend up to 4X times more to get 5% doesn't make it necessary. Intel RAM scaling has sucked for years.
Optimal Zen performance requires faster RAM, hence the discrepancy. 3600 is recommended sweet spot on these new AMDs for optimal performance and that is more expensive. Even if you buy the cheapest 3600.
Other than that, you just said the same thing I did. Platform price for equivalent quality and performance is basically the same. But I see so many comments on how much cheaper AMD is. Its not.
But maybe Intel will take some older Coffee lake parts and start a price war. Just like they did with Pentium D when X2 ate their lunch. That would be awesome
There is going to be very little to no difference between 3200 and 3600. Heck even 3000 might not provide a real tangible performance loss in the vast majority of applications.