Regarding internal developer platform adoption and the Backstage example, I think the point that gets lost a bit is that you have to actually create a better product and experience. I've seen multiple developer platforms that are somewhat helpful but also somewhat awkward to use and have missing use cases, out of date documentation, and various other warts that hinder adoption. Open sourcing may be a plus, but primarily you have to put in the investment and care to make it good, just like externally-facing products.
Regarding internal developer platform adoption and the Backstage example, I think the point that gets lost a bit is that you have to actually create a better product and experience. I've seen multiple developer platforms that are somewhat helpful but also somewhat awkward to use and have missing use cases, out of date documentation, and various other warts that hinder adoption. Open sourcing may be a plus, but primarily you have to put in the investment and care to make it good, just like externally-facing products.