See some of the Dell thunderbolt docking stations here https://www.digitec.ch/en...

I had the same question; If there are HDMI, VGA and Display port why 2 monitors are not supported - but it could be related to the absence of power as this dock does not support USB-C power throughout. This is supposed to be a light travel docking, so a compromise was on the connectivity options rather than an additional feature. There are some Dell desk docking stations that support up to 3 monitors - but I don't know if this is what you are looking for.

Cheers!