A monorepo is a transfer of convenience from people who make services to people who make libraries. A library author's change automatically runs the tests (pre land) and CI/CD pipelines (post land) of every dependent service, where previously it would have taken months of wrangling to distribute a library release this widely. But service author laptops are now struggling under the weight of every line of code at the company. Git operations take long enough for you to lose interest and tab over to HN. After a git pull, many of your dependencies have changed which can break things (at worst) or just invalidate a lot of cached compilation and make the next build slow (always). You need the build system to generate a "mask" for your IDE so that code intelligence doesn't try to index the whole thing in memory, etc. Buck and Bazel are less familiar and less ergonomic than languages' native or customary toolchains. You need further tools (or a lot of manual effort) to keep the monorepo build system's own configuration files in sync.
