Lot of people have complained that Google search is worse today without Reddit. If Reddit management kills the communities which produce the text posts it could have a real negative impact on Google.
Meanwhile Google's text and video ad network could probably monetize Reddit way better than Reddit can.
The fundamental problem is that reddit's primary strength, it's biggest point of value, is antithetical to the type of monetization that Google would implement.
That is actually really true.
Also reddit is a great (if not the actual best existing right now?) source for training AI models.