Possible guess: Probably because the Andersons are so expensive compared to the IEC, and so much better for the DC application they're intended for, that there aren't enough people that need one (instead, they just replace the one with the other).
There is this
https://www.amazon.com/SAF-D-Grid-T-Latch-Plug-IEC-14AWG/dp/B08ND234PL
but it is not for the SB50 type of Anderson.
You can make one easily enough by splicing together half of a IEC extension cable and an SB50 connector already wired up. This article
https://www.electricbike.com/connectors-halls-throttle-motor/
and this post
https://endless-sphere.com/forums/viewtopic.php?f=2&t=86600&p=1463159&hilit=solder%2A+phase%2A+stromer#p1463762
show some ways to splice heavier gauge wires together, that work pretty well.
KDKD said:
BTW, I don't know what you do for a living but if you aren't already an engineer, you would make a GREAT one!
I pick and pack and ship internet orders.
Everything else I do is a hobby (haven't found people to pay me a living for anything else I'd want to do, especially my music).
I have a wierd brain that doesn't work like most people's, so I don't fit well with them; makes it tough to get "in" anywhere (once I *am* in, I stay until the place itself goes away for whatever reason, while everyone else changes around me).
I also don't operate well in realtime; I do best "offline" where I can think out my disorderly way and edit myself together. (everything I do well is done this way).