I think with Apple, Amazon, Microsoft and Google, you have a good competitive landscape to work with right now. All of these players already making their own chips. ~4 solid verticals that are somewhat compatible and highly competitive with each other in large, mostly-overlapping regions.
Honestly, things feel pretty OK to me when you factor it all in. If it was just Microsoft or Apple doing the vertical chip thing and they were going absolutely hockey stick over it, then perhaps. But there are several competent players doing this now.
Mandating that SW/Services companies be forbidden from silicon is every bit as absurd as prevention hardware manufacturers from toching software. The playing field for software is incredibly level these days - everyone uses the same IP vendors, design services & contract fabs.
If you want smaller companies, reform it'll be much easier to get rid of tax pyramiding that favours mega corps.
I'm not arguing that at all. Just that they shouldn't cross so many markets at once.