There are NO external pcie expansion ports which can be connect via usb and hdmi. Pcie requires pcie protocols to be used on the port. This limits pcie adapters to mpcie (usually used for the wireless card on laptops), expresscard (old, phased out and no longer on any laptops for a couple years now), m.2 nvme (msata replacement used for ssd, many laptops don't have it), and thunderbolt (the only external connections while the others are internal but many laptops don't have and expensive adapters $200+).
Pcie x1 is 1/16 the bandwidth but this translate to 50% performance. If you check benchmarks, many games are actually not getting down to 50%.