There are a few considerations here.
First, usually the marketing folks only highlight the peak performance, the sustained performance is often (much) lower, no matter the device. Especially for write operations as writing is still much slower in flash memories than reading.
Second, this Samsung seems to be a real SSD, so I guess (*) several architectural enhancements are used to obtain high performance: a decent internal microcontroller with very optimized firmware, reasonable amount of RAM cache, paralleling access of the flash memories in relatively wide internal bus, not to mention the use of multilevel bit storage, pretty common nowadays for cost reasons but that has the R/W access speed advantage byproduct.
Third, the USB 3.x interface have a pretty high transfer speed, as it has additional high speed differential lines. This Samsung uses USB type C connector, so there up to four high speed differential lines so the data is split between them and thus potential transfer speed is pretty high. There are no hubs involved for some or all of these ports, in modern hardware, AFAICT. Other high speed interfaces (e.g. Thunderbolt, HDMI) are supported by the type C USB, but I guess the USB 3.x is used.
OTOH, conventional, cheap USB sticks (even good quality ones) have more limited capabilities. Those limitations, more than the USB hub itself may limit the transfer bandwidth.
Just out of curiosity, I just made a little experiment, I copied a relatively big (4GB) file from a USB 3.x thumb drive (Sandisk - 3 or 4 years old) to the SSD of my laptop (6 or 7 years old), and the transfer speed was 127MBytes/s according to Windows. Pretty decent, I think a read only transfer such as streaming from stored samples would be even faster. So... maybe, MAYBE, an external USB 3.x flash drive of decent quality could work, depending on how the USB 3.1 port is routed inside the PC. However, unlike the copy operation of big files that is sequential, the streaming of samples may be random so, again, internal limitations of the drive may cause a lower transfer speed, despite the read-only nature of it.
(*) I do not follow the details of IT technology stuff nowadays as I used to when I was young, though I develop technology myself in a different, more fun (IMO) area.
It’s a false dichotomy.
Some external USB/ thumb drives have SSD inside them.
Samsung T7 Touch Portable SSD 500GB - Up to 1050MB/s (write speed) - about USD $50-60.
To be honest: you’d have to be ultra poverty-stricken to purchase anything slower than that! (For any purpose - not just VSTs)