You mean sentient AI?

Blake Lemoine's claims were dismissed by experts in the field.

Google has good AI research but there are plenty of others. For example, look how many companies have poached or been started by the big brains that kick started google AI. Andrew Ng (Google brain co-founder) or Ian Goodfellow for easy examples.

AI is a field you can buy your way into. Poach smart scientists and buy/rent computing power, then sell your AI product or service. Building a user base is much harder, which is the reason Elon bought Twitter instead of starting new website, to bring this back to original question.

Google is an advertising platform. Twitter is an advertising platform.

The features you list are to engage eyeballs to view the ads, and to collect massive amounts of user data to more efficiently deliver the ads. These increase the advertising rates they can charge.