8GB of RAM is too little for a Windows 10 PC full stop. If you can afford it, then you should definitely purchase more.
Minimum and Recommended spec for TSW2 is 8gb of Ram CPU and GPU upgrades would provide the most benefit towards performance, while more Ram, it appears, won't help very much if at all.
While a CPU or GPU upgrade will of course be a more noticeable upgrade I would also argue that 16GB of RAM is the minimum anyone gaming on PC in 2021 should have.
If you're out of RAM, your PC will start using the pagefiles on your HDD, and those are really slow compared to RAM, so the game will start stuttering really bad. As others have said, you're better of with 16GB of RAM. 8GB is barely enough for most games nowdays.
No arguments, if you are out of RAM, performance will suffer. More games these days are requiring 16GB as a recommended spec. The question was in regards to TSW2 and not other games. If you have excess RAM, you won't see any performance increase either, the game uses the amount of RAM is uses and having extra doesn't change that. Windows 10 minimum requirements to run is 2GB of RAM on 64bit. TSW2 appears to uses approx 2.2GB of RAM while running. 8GB is more than enough headroom to run windows 10 and TSW2. But, if you are running other background programs, you may find 8GB becomes a squeeze. So no harm in having more than 8GB RAM to cover whatever your PC is running at the time of running TSW2. However, if you have your background processes under control and manage what programs are running, then 8GB is more than enough and going to 16GB won't see any improvement in game performance.
I would suggest 16GB is a reasonable amount at the moment. If the OP really has 8gb i.e. 8 gigabits of RAM (= 1GB) it's far too low. I realise I am being pedantic. But it's a pet peeve of mine because when it is less obvious that the information is inaccurate, it can cause all sorts of confusion. Not sure if network speeds will always be measured in bits per second. Until that is not so, it can be confusing.
They're telling porkies. 16GB hard minimum, if you want more than around 10 fps on München-Augsburg or Clinchfield or the Rush Hour routes