Illustrator's performance issues on macOS BigSur

Hello. I typically use PC, but am doing some work for someone and using my mac. I have a macbook pro 2020, core i7. I consider this to be a capable machine but have to say the suite of adobe apps on it is just abysmal.

Illustrator:

1. Prefs do not save. I can set it to say mm as units and on next restart its back to points.

2. 50% it crashes on exit anyway

3. Really slow to use, like not a pleasant experience, menus, key strokes everything is just syrupy.

4. If you have links panel up, it gets even slower

5. If I restart the mac it will play nice for a short period, but its like there is a memory leek or something and gets worse. 

It geuninly feels like I am trying to run illustrator on an ancient laptop, what ever peoples opinion of apple are it should be a capable laptop.

Whilst I am here:

Why no spell check in this forum, this is 2021.

Why do we have to have a specific adobe app for 2 factor, its not necessery and only supports one account. I am using 3 accounts. Just gives us typical 2 factor we can add to our authenticator app please.

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