In the 3 years since I wrote my post on Bazel, there have been a few changes to the Bazel ecosystem:
1) I've met many more large engineering orgs that have either partially adopted Bazel, or are investigating Bazel.
2) There are several different companies that build tooling around Bazel and consult with teams on how to use it. I've talked to the folks at flare.build and EngFlow. There are more listed here: https://bazel.build/experts.html
If you're a large company looking into Bazel, that's a lot of good news! There are more peers you can learn from and help you can ask for! If you had asked me 3 years ago, I would not have predicted the ecosystem to grow as much as it has.
But I think my high-level criticisms of Bazel still stand. The Kubernetes project deleted their Bazel code in February 2021. They wrote this doc that I mostly agree with:
A lot of their criticism is from the point of view of a majority-Go open-source project. They've had trouble getting Bazel to interoperate with stuff "outside" its model. The remote cache can be troublesome to operate and optimize. I've heard these same criticisms privately from other companies.