Is 24gb enough ram on a new Macbook Pro m4 to run lots of VSTis and mix?
You only ever need a lot of RAM if you use sample libraries. Plugins don’t use much RAM.
So, Yes, if you don’t use libraries, No if you do.
As a general rule of thumb, buy as much as you can afford, just in case you change your work practices in the future.
It also depends on if the library loads into ram or streams from disk. I use SD3 drum vsti and it loads to ram kits which can be quite large (mine are around 4gig but can be a lot more)