Just like one diversifies their investments, clearly it pays to diversify services you use as well. Which is the exact opposite message companies like Google push: "use us for everything, it will be convenient!" Until you lose everything in one fell swoop.
I do not comment on google platforms at all because I’m so stuck with gmail due to making an account when it came out and I was young then. Whenever I have a choice I avoid their products.
I’m even avoiding publishing hobby stuff on Play Store nowadays as a bad submission due to error will, you guessed it, lead to total ban.
Just as you said this works against their interests. As consumers we must diversify.
Not diversify, just stay away from any provider with multiple services, poor customer support, and a penchant for banning accounts for code of conduct violations.
Losing an email address or even access for some time will cost me money. Gmail isn't good enough that I'd risk my business over google code of conduct.
But any of those negative attributes could apply to any provider at any point in the future, even if they don't now. Best to actively avoid all your eggs in one basket to the extent possible.