Thunderbolt 3 versus USB Type‑C external SSD, is there difference for MBP 2019?

Solution 1:

Below are answers and comments based on the OP's posted question.

I understand that Thunderbolt 3 is much faster in data transfer than regular USB Type‑C, but can the SSD utilize this difference?

Thunderbolt 3 is up to 40 Gb/s and USB 3.1 Generation 2 is up to 10 Gb/s. The SSD used in both the Samsung T7 and X5 Portable SSDs is faster than 10 Gb/s. Therefore, the SSD can utilize this difference.

Should I pay extra for Thunderbolt 3 external SSD or if I purchase a USB Type‑C SSD, then I will not feel the any difference?

The Samsung X5 Portable SSD will be notably faster than the Samsung T7 portable SSD. Also, the Samsung X5 will appear as a NVMe drive with TRIM support just like the internal drive already in your Mac. Although, the internal drive will be slightly faster than the Samsung X5. The Samsung T7 portable SSD will appear as a USB drive. I have not found any indication that the Samsung T7 has TRIM support.

Another consideration is back compatibility with older hardware. If I understand correctly, USB Type‑C <=> USB 3.0 adaptor is a much cheaper and more widely available than a Thunderbolt 3 <=> USB 3.0 adapter.

The USB Type‑C <=> USB 3.0 adaptor is just a cable. This cable is included with the the Samsung T7 portable SSD. I am not sure a Thunderbolt 3 <=> USB 3.0 adapter that would connect a Samsung X5 Portable SSD to a USB 3.0 port exists.