The question is "speed increase compared to... "
I think I was talking about getting from my old 2014 mac to my 2019 one.
As I described above, there was a nice increase, but it had to do with the limitations of the old mac.
In your present case, the limiting factor is no longer the mac - your Thunderbolt 3 ports could theoretically support 40Gbps.
The limiting factor is the drive itself. It supports USB 3.1 gen 2 - which can give you up to 10Gbps.
Thunderbolt 3 uses the same connector as USB-C, and supports USB-C type connections, at up to 10Gbps.
Now, you could get yourself a much more expensive SSD that uses Thunderbolt 3 protocols, and might get you some 2500MBps - close to what your internal drive offers. OWC has some great ones.
Personally, I don't see the point, unless you are really feeling constrained in your workflow by the present drive.
For what I do, my Crucial drives are more than enough. I, the human, am the limiting factor, not my hardware.