Very few people understand the extent of how many bad actors there are until they experience it firsthand.
That said, Google and Microsoft essentially have monopolies in their respective areas of the market (Gmail in consumer, Outlook in B2B), and if you think they aren't slowly letting these products decline while cranking up the revenue extraction...you're dead wrong.
With LLMs they could eliminate spam in a much more reliable way without killing off small senders, tomorrow. Yet, they will never devote any real resources to these products, since they don't have to. Nobody wants to go through the hassle of changing their email.
Outlook still uses the Microsoft Word HTML rendering engine, completely unchanged, from 20 years ago. That's all you need to know about the incentives for innovation after you've successfully captured a network.