The fab was also in-house.
"It is DEC's first single-chip microprocessor implementation of the VAX ISA and DEC's first self-fabricated microprocessor...
"The MicroVAX 78032 contains 125,000 transistors on an 8.7 by 8.6 mm (74.82 mm2) die that was fabricated in DEC's ZMOS process, a 3.0 µm NMOS logic process with two layers of aluminum interconnect."
Interesting to compare them both with the ARM1 which was 32 bit (no MMU) but only used 25k transistors on a 3 µm process - and which was more powerful than VAX 11/780. So both powerful and cheap to make.
I think DEC was the first third-party implementation with StrongARM.
I think everyone eventually had their own RISC - IBM, HP, AMD, Intel (i960) plus MIPs and SPARC of course and a few others.
Arm eventually got traction because of the business model and because they intentionally didn't go head to head with the Intel x86 juggernaut. It wasn't obvious for a long time that their model would work though.
The 801 experiment SPARCed an ARMs race of EPIC proportions to put more PRECISION and POWER into architectures with MIPSed results but ALPHA's well that ends well.
DEC sued Intel for patent violations and won. Digital was dying, and part of the settlement was that Intel purchase the billion dollar chip fab in Hudson, Massachusetts that was just built to produce the chips, and later demolished it in 2015.
So despite the fact that i386 was now capable of really useful and intricate segmented memory architecture, it was the unsegmented, flat virtual address space that won the race.