Answer could well be yes since build time impacts everyone, but also have to factor in complexity of the CI system they use.
Long build times are an operational risk - it's very hard to apply patches to solve incidents with a 20 minute build time.
I agree though, definitely a factor
Because THAT'S the hard problem to solve in any bigger organization. Not hacking the code.
Maybe, or just a knowledgable person to dig in for a bit and solve it. On one of my teams when I was back at Microsoft was working on a similarly huge codebase with build times twice as long. We had a senior engineer who was really into build optimizations from a previous job who wrote a tech design, implemented better project splitting in our monorepo, better local caching, and finally cloud caching, all within 3 months. When I left, our builds ranged from 30 seconds to 3 minutes.
It's not guaranteed that it'll be this simple, but I also don't think it's guaranteed it'll be 3 years and several people.