Thats my situation. We're 5 devs for 5 years on a monorepo with about 50 services and worked on master without problems. Just from time to time a merge conflict.
The only difficulty is to manage Release branch(es) with hotfixes.
Discipline, Thinking and Working together, that's the magic source.
especially combined with monorepo
amount of time people spend updating dependencies between internal services and libraries in a pursuit of semver for now reason is just absurd