An "AI winter" like we had before isn't plausible now. In the past, it was the failure of AI research to deliver business impact. The current ML boom is fundamentally different in that it already has become a standard part of the stack at major companies:
- Recommendation engines (Google, YouTube, Facebook, etc.)
- Fraud detection (Stripe, basically all banks)
- ETA prediction (Uber, every delivery app you use)
- Speech-to-text (Siri, Google Assistant, Alexa)
- Sequence-to-sequence translation (used in everything from language translation to medicinal chemistry)
- The entire field of NLP, which is now powering basically any popular app you use that analyzes text content or has some kind of filtering functionality (i.e. toxicity filtering on social platforms).
And that's a very cursory scan. You can go much, much deeper. That isn't to say that there isn't plenty of snake oil out there, just that ML (and by extension, AI research) is generating billions in revenue for businesses today. There's not going to be a slow down in ML research for a while, as a result.