Here my comments for a dock-focused overview.
USB-C Alt Mode Docks: USB Bandwidth can never be 20 Gbps, because then there would be no DP.
TB3 Docks:
I would distinguish old / Alpine Ridge and new / Titan Ridge.
Alpine Ridge is limited to HBR2. I have no experience with Alpine Ridge Docks, but with my Asus Alpine Ridge PCIe Card there is a problem if the monitor and host support HBR3, because they seem not to detect the limitations by the TB controller (even for directly attaching the display, without an actual TB connection in between). This resulted in flickering black screens and the pc endlessly redetecting the display, without me being able to change any of the display settings. So I would be careful getting Alpine Ridge for newer hosts, might be a timebomb, if displays are ever upgraded. Also earlier Alpine Ridge firmware versions prevented HDR.
Titan Ridge on the other hand is backward compatible to USB-C DP Alt Mode hosts, which increases compatibility with other hosts, such as cellphones or cheaper laptops, or AMD based laptops for the time being. Also one hears much less about the docks stopping to work after a while or being as finicky.
TB4:
most things you list are guarantees of a TB4 host, not a dock.
TB4 Docks do not require TB4 hosts with PCIe tunneling. They will also work on USB4 only hosts in the future (so far I am not aware of any TB4 dock using the x1 PCIe port Goshen Ridge provides at most).
TB4 Docks do nothing for DMA protection. In fact they do not need it, because they are not using PCIe (if connected via USB4/TB4). This should allow booting from USB sticks behind TB4 docks, without having to enable non-default and quite insecure options such as PCIe BootROM support behind TB, as was necessary on TB3 hosts in order to get this working. This of course only works with TB4 docks. Sadly my desktop PC has no option to allow booting behind TB4, but this should be distinct from the technical capability.
Wakeup from sleep states means, waking up from USB devices such as keyboard or mice behind TB4 docks. (probably through the USB2 connection separately kept, which TB3 does not have).
My TB4 host will not wake from sleep from keyboard interactions behind my TB3 dock, but will from my TB4 dock. Certain manufacturers have implemented workarounds for TB3, such as my Dell XPS with my WD19TB. I am guessing the wake-on-USB is handled by the dock and communicated via PD in the same way the proprietary power LED and button of the dock is, because there is multiple seconds worth of latency, compared to using the builtin keyboard.
Also, TB4 devices cannot be put behind TB3 devices, because then they operate in TB3 legacy mode, which forces TB4 docks use PCIe instead of USB tunneling again and would prevent such things as waking from standby.
This leads me to recommend TB4 for anything that supports daisy-chaining, because it would be a hard to detect this TB3 limitation later (although it can be exploited to increase USB-bandwidth, which is actually limited to one 10G USB3 link per TB4 port. I did some testing with maple ridge + goshen ridge).
TB4 mandates active cables be backward compatible to USB3 and DP, while TB3 only mandated USB2 support. But the spec excludes fiber-optic cables from that, those do not even need to support USB2 (or power). But passive cables are probably more future proof for DP 2.0 or not yet specific things (I do not know how precisely the active cables work, whether they are protocol aware or only work for specific frequencies…)
A completely different aspect: Tiger Lake supports Adaptive Sync via DP with modern G-Sync / FreeSync displays etc. So far, every dock I have heard about that includes MST Hubs breaks this functionality (raw output via TB-out not affected). On Intel one can still enable Adaptive Sync, but the screen turns black as soon as the GPU actually tries to go below the main refresh rate. Also docks with builtin DP-HDMI converters might be picky with the supported HDMI displays. My Dell WD19TB for example does not like my Ultra-Wide screen display on the builtin HDMI. Exotic monitors are usually not tested for with those docks. If you care about this, one should get a dock that offers the native TB-Outs or raw DP-Ports. If a TB dock currently supports more than 2 displays or HDMI it contains MST-Hubs and adapters that will most likely mess with some exotic functionality.