You will probably need one someday, but it’s not going to save you from yourself. The take home is it’s still a decent computer and with the same file of 37 million edges you would likely not see an enormous improvement for the cost of a new computer. Your discrete graphics card is also not terrible. Ram would help you, 16 is on the low side but workable. SketchUp runs on a single core of your processor, so more cores will not help, processor speed will, you are at 2.5 which is really not too bad, if you went for a newer MBP in the 3’s you might notice, probably not.