I prefer not to build USB devices which enumerate as COM ports because:
(1) It can be a hassle for PC software to automatically find which COM port is used by your device, in the worst case opening each port and trying it. I think there is some option to find the descriptor strings / friendly name supplied by your device which would help but is not straightforward. Whereas for a USB device, you can just open by VID:PID.
(2) Using WCID is just as easy as CDC from a firmware point of view and also from host point of view i.e. plug 'n' play for both.
(3) With a WCID USB device you get a sensible device description in Windows Device Manager (string of your choice, e.g. you can include your company name, device name, sn).
(4) With a WCID USB device you get as many endpoints as you want which helps with separation of concerns in firmware and software. CDC is one data endpoint.
(5) With a WCID USB device you can use all transfer types (control, bulk, int, iso) and I find vendor commands on EP0 useful. CDC is bulk only.
(6) With a WCID USB device you get FS or HS. CDC is FS only. Edit: Apparently CDC is also FS or HS.
(7) Creating commercial products in 2022 which use COM ports looks weird and unprofessional IMHO.
So, in summary, for USB devices connecting to Windows, WCID is just as easy as CDC but offers more features.