No one knows for sure. 2017 was the mega-bubble ICO craze. 2021 is primed to be the DeFi and institutional investment craze. If I had to guess, I'd say that 2025 will be the mega-bubble fueled by gaming. Perhaps 2029 will be the "mainstream adoption" phase. Who knows? My guess is as good as any's.

Probably right. Blockchain gaming isn't exactly going mainstream, yet. The idea is compelling, though. Being able to trade everything on an open market and security from having one's account being canceled should be really attractive to all serious players.