I think Fusion is very good for creating tool paths and strategies for CNC machining (probably the best bang for buck for small volume) and I think Inventor is very good at 3d design.
I haven't used Fusion for design because I have inventor but it does strike me as strange that the 3d modelling workspace of fusion is so different to Inventor. I don't use fusion very much, only for G Code, we outsource mass machine work but I do prototype quantities in house and fusion with the 5 axis add on is too expensive so I use it day by day as needed with prepaid tokens to save costs.
I HATE that you have to buy subscriptions.