Observations:
For dx11, you can see that the average, minimum, maximum, 1% low and 0.1% low framerates have all reduced. Though, this is by a small amount (around 4-8%) and not necessarily unplayable.
However, for vulkan, it is much worse. The average, minimum and maximum framerates are all 10-20% lower. The 1% low and 0.1% low are extremely bad, at a whopping 80-90% drop.
Furthermore, there have been frequent instances of the game completely freezing for 1-3 seconds since the past few weeks. This is on dx11 (which I normally play on), although I don't know if its happening on vulkan as well.
Benchmarks:
System configuration:
Model: Lenovo Legion 5
CPU: AMD Ryzen 7 5800H
GPU: NVIDIA GeForce RTX 3050 80W+15W
RAM: 16GB DDR4
Storage: 1TB Samsung 970 EVO Plus PCIe NVMe M.2 SSD
Note: Pimpmuckl's
Source: https://www.reddit.com/r/DotA2/comments/s8nyco/dota_2_benchmark_comparison_before_and_after_aghs/