Just because SoftBank own it now, do you really think if Europe went to it and said "can we buy half, if so we'll buy $X amount of licences otherwise we'll start (effectively) a serious competitor in risc-v.
Again why to fight for ARM where Softbank will want a huge payoff. When you can instead put this money into RISC-V. I guess i am comming from viewpoint that what EU really needs are independent chips that don't have to be the most cutting edge. I think performance few years behind is fine for majority of needs and that would make europe much more independent. So chips for AI no but for everything else it would be a great start.