AMD knows Intel is kind of f'd for the better part of the next two years so we get to pay the price for lack of credible competition.
Supposedly Intel may be leaving Hyperthreading enabled for all of their "10th gen" Core processors and filling the i9 level with a 10-core model, and if that's the case, they will likely be back in the game around the end of the year. Power consumption and heat output will likely be relatively high with all threads loaded, and aftermarket coolers will probably be needed to get the most out of them, but that's not much different from their current lineup. Once Intel is matching the same number of cores and threads as AMD at relatively similar price points, their products should be a lot more competitive.
Yeah, how can there be a Zen 2+ when these Ryzen 3000s are already maxed out of the box?
Replacing the stock cooler with a high end one doesn't really do anything for performance, save for lower noise.
They'd be pulling an Intel at that point.
Zen+ was more than just raising the stock clocks on existing processors. What enabled those higher clocks was the move to an updated manufacturing node, and likewise we should see clock rates go at least a bit higher for the 4000-series processors as well. Zen+ also incorporated some changes that enabled improvements to memory latency, among other things, and similar changes will likely improve IPC a bit for the 4000-series as well. I doubt the 4000-series will provide as large a jump in performance as the 3000-series, but there should be room for some improvements.
As for AM4 support, I suspect next year's processors will likely continue to support existing motherboards, at least the 500 chipset boards. My best guess is that there will be new boards to support DDR5 in 2021, assuming that RAM is readily available at reasonable prices by then.