I agree. In my opinion, if you can keep the experience of Bazel limited to build targets, there is a low barrier to entry even if it is tedious. Major issues show up with Bazel once you start having to write rules, tool chains, or if your workspace file talks to the Internet.
I think you can fix these issues by using a package manager around Bazel. Conda is my preferred choice because it is in the top tier for adoption, cross platform support, and supported more locked down use cases like going through mirrors, not having root, not controlling file paths, etc. What Bazel gets from this is a generic solution for package management with better version solving for build rules, source dependencies and binary dependencies. By sourcing binary deps from conda forge, you get a midpoint between deep investment into Bazel and binaries with unknown provenance which allows you to incrementally move to source as appropriate.
Additional notes: some requirements limit utility and approach being partial support of a platform. If you require root on Linux, wsl on Windows, have frequent compilation breakage on darwin, or neglect Windows file paths, your cross platform support is partial in my book.
Use of Java for Bazel and Python for conda might be regrettable, but not bad enough to warrant moving down the list of adoption and in my experience there is vastly more Bazel out there than Buck or other competitors. Similarly, you want to see some adoption from Haskell, Rust, Julia, Golang, Python, C++, etc.
JavaScript is thorny. You really don't want to have to deal with multiple versions of the same library with compiled languages, but you have to with JavaScript. I haven't seen too much demand for JavaScript bindings to C++ wrappers around a Rust core that uses C core libraries, but I do see that for Python bindings.