Here's the issue... Being able to track commits across multiple projects is just a nice to have. Does it even significantly increase your ability to track dependencies or trigger down stream tests? You can track that stuff with multi-repo automations. Maybe it helps a bit but it's not free and its not complete.
Your deploys don't become atomic. Your builds don't become atomic. At best you get to tell yourself you can version a bit more loosely.
Mono-repos themselves do not scale easily. Inherently its a harder technical problem to solve. You need to toss git and find something better, which is not easy. Its work. Its so much work that it is incredibly clear that you've never experienced it yourself.
Your deploys don't become atomic. Your builds don't become atomic. At best you get to tell yourself you can version a bit more loosely.
Mono-repos themselves do not scale easily. Inherently its a harder technical problem to solve. You need to toss git and find something better, which is not easy. Its work. Its so much work that it is incredibly clear that you've never experienced it yourself.