I went from using a 2014 MBP with three monitors (two Dell 2717H/HX monitors flanking a 34" LG Ultrawide), and I wanted to basically just drop the 16" into this setup, but I thought if I could get everything connected via one or two cables instead of taking up all my ports, it would be a nice bonus. My attempt to use an HP Thunderbolt 3 dock did not go well, as I have detailed in another thread here. It was not possible to use both of the DisplayPort ports on the dock at once (trying would only result in mirroring). But more disturbing was that even when I was just using one of the ports on the dock, I would get weird behavior when waking from sleep. Sometimes one or the other display would not turn on, and at least once I got into a weird state where all of the monitors would turn on for a couple of seconds and then turn off in a loop.
I have read enough horror stories to know that a lot of people are having trouble with a lot of Thunderbolt 3 docks (something I attribute to bugs in Catalina), and this has made me very reluctant to spend upwards of $200 to get another dock that may have issues.
However, I tried using a "plain old" USB-C hub with HDMI from Lenovo, and so far it has worked fine for the last 2+ weeks. I have the power cord plugged directly into the MBP to ensure that I get enough power, the USB-C hub plugged into another port, and the other two monitors plugged directly into the remaining two ports. I have a couple of regular USB hubs daisy chained to the USB-C hub, and that's where I have my legacy peripherals. I haven't had any issues with displays not turning on or flaking out, and the other peripherals seem to be working okay. So it is possible to have a stable 3-monitor setup, but at this point I am a bit suspicious of Thunderbolt 3 and multiple displays on these machines.