Do you occasionally transfer many memory cards at the same time? Do you also need a Thunderbolt dock that allows you to attach multiple peripherals to a computer with a single cable? Well, I have the perfect product for you.
The Pro-Dock 4 is a Thunderbolt 3 dock with four empty bays that accept custom-shaped memory card readers that can be purchased separately. These "Pro-Reader" modules have a standard USB-C jack on the back that allows them to be used on their own, or they can slide into the dock to be used without a cable. Currently, SanDisk sells a multi-card reader with CF, SD, and MicroSD slots, a CFast reader, a CFexpress Type B reader, and a Mini-Mag reader.
The dock itself is full of ports. On the back, you have two thunderbolt ports, one DisplayPort, and an Ethernet port, and on the front, it has a headphone jack, two USB-C ports, and two USB-A ports. 
I like using dual monitors with my home setup, and I was frustrated that the dock only had a single DisplayPort option. Luckily, I was able to use a USB-C-to-HDMI cable to get my second monitor up and running. Interestingly, this cable does not work in the front USB-C ports but does work with the Thunderbolt port on the back.
I've been using the Pro Dock 4 with my M1 MacBook Pro for about a month now, and it has worked flawlessly. The only thing that keeps me from recommending this product to everyone is that few people need four memory card readers, and if you don't, $499 for a Thunderbolt dock is a high price to pay. 
I hope that SanDisk adds two accessories in the future. First, they need to sell a USB-C extension module for unused memory card ports. For those of us who don't need to use all four slots for card readers, having additional USB-C ports in the front would be great, but currently, the USB-C ports are too far back in the housing to access.
Finally, SanDisk needs to sell SSD memory modules that can replace the memory card readers. Not everyone needs four memory card readers, but almost everyone working on a laptop needs additional memory. Of course, SanDisk makes tons of solid-state memory, and I find it very strange that they don't currently sell additional memory modules for this dock.
With these two additional accessories, I think this would clearly be the best Thunderbolt dock currently on the market, but as it stands right now, the Pro-Dock 4 is the best Thunderbolt dock if you also need to transfer a bunch of memory cards at the same time.
Can't you daisychain the displayport on the reader?