> Linux just has far far more commits and files to deal with
Not really. I work with Mercurial every day, in a FAANG company's monorepo which is many many times the size of the Linux kernel. It's not always pleasant, but it's not clear git would be any better. Mercurial's performance issues are solvable, have been solved to a large degree, but IIRC when git started that was not the case. It's a shame really. The fragmentation is annoying sometimes, even if it's the result of historical accident rather than any bad decisions made at any particular moment in time.
Not really. I work with Mercurial every day, in a FAANG company's monorepo which is many many times the size of the Linux kernel. It's not always pleasant, but it's not clear git would be any better. Mercurial's performance issues are solvable, have been solved to a large degree, but IIRC when git started that was not the case. It's a shame really. The fragmentation is annoying sometimes, even if it's the result of historical accident rather than any bad decisions made at any particular moment in time.