November 2020
I bought an SSD (Samsung T7 Touch 500gb) and I found out that you can store games on it as well (my laptop has 128gb SSD so it was necessary). I downloaded all my sims games on the external SSD and voila it worked!... sadly I did this after the new update and I thought the SSD was the problem (with all the crashing) but it was not. because of all this I don't know how sims 4 really works on an external SSD (the loading screens and speed) so if some of you have experience with this please feel free to share!
November 2020
@skullgirl111 My experience is a bit different: I installed another operating system on an external hard drive and left Sims 4 on the internal drive. (Actually, I installed a few OSs.) So it's not exactly what you did, but the OS and the game are still communicating over an external SSD connection. Sims 4 runs great; I don't notice any performance hit at all. However, my SSD is very fast and has an equally fast connection, so that's not surprising.
There are ways to test external SSD speeds, and if yours is slower than the drive itself, you might be able to get a better connector. But there's not much point in trying until you've addressed the crashing (or EA has). If you happen to have this issue:
there are workarounds available; see post 2 for a link.
November 2020