Google's acquisition strategy is to acquire smaller payment rail payment companies through medium tier businesses and use their acquisitions to create revenue engines like AdSense. The company had enough capital market scale to make multi-billion dollar purchases and build its empire.
The absence of big tech M&A will shift valuations for late-stage private startups and make it healthier for the entire ecosystem if they aren't built to be flipped but merged with slightly stronger medium-sized companies and then taken public.
Google's revenue engine was built through acquisitions, including Applied Semantics which became AdSense. Big tech companies like Google have realized they struggle with R&D and rely on acquisitions for new product development.
The current rules for regulating M&A for big tech companies are inadequate due to their market share not being above 95%. A proposed rule is to allow medium tier businesses to buy payment rail payment companies to avoid monopolistic behavior from larger companies like PayPal.