DeFi: Very interesting long-term, but the infrastructure isn't there yet - Ethereum (or alternative) needs to scale, and there need to be better ways of representing real-world things on the blockchain. I'd say at least a decade off, and could go the way of the 2000-2005 P2P boom (note though that that boom had some very lasting effects: Bittorrent, Skype & VC, DVCSs like git, and Bitcoin). We'll probably have periodic bubbles and busts until then. May get some help from Fed policy. If it succeeds it will revolutionize everything - the financial sector is 25% of American GDP and our primary export, features a lot of moral hazard and grift, and smart contracts enable some forms of commerce we haven't seen before.

Drones: My 3-year-old will ask me "Daddy can you fly the drone now?" and absolutely loves chasing it. Great toy now, starting to find some industrial uses with insurance/forestry/firefighting/etc. Will absolutely revolutionize warfare when the next war happens.

Self-driving: Another wartime technology. I think this will limp along in niche markets until then, and then explode (no pun intended) when we need to maintain logistics networks under armed threat. Likely to be a cornerstone of post-war transportation networks, but not in the form they are now. Rather than struggle with sensor algorithms, we'll likely build the sensors & coordination into the road infrastructure and ban manual driving.

Robotics: This is like AI in that when it succeeds, it's no longer called "robotics". It's already used very extensively in manufacturing and logistics (have you ever looked up airport baggage handling systems on YouTube?). We aren't going to get general-purpose robots, but we might see a wave of micro-manufacturing appliances a la 3D printing (put in raw materials, get back a product made to your specifications, distribute products digitally) as well as descendants of today's household appliances (we already have this with Roombas, robotic lawn mowers, robotic tractors, etc).

EVs: Will probably go mainstream around 2023-2024. If you're already a top-notch electrical engineer you can likely get very rich on this right now by founding a company and letting a SPAC take you public next year. For the rest of it the excitement will be in buying one and upgrading our solar panels, power wall, power grid to support it.

Climate tech: Will likely ultimately fail in stopping global warming but will invent lots of useful innovations that might be applied to other industries in the future (sort of like how microwave ovens came out of radar and computers came out of artillery guidance). If you have good skills and a long time horizon, the play is to go work for one of these companies, learn everything you can, spend your time researching, and then ride it until it goes bankrupt and then apply the technologies toward something more mundane.

I'd agree that we're not in 2005 now - it feels more like 2002-03, where you can tell that there's interesting stuff going on but nothing's really ready for primetime yet. We had stuff like Friendster, Kazaa, LiveJournal, BaseCamp, then - all precursors to really important stuff, but the specific successes hadn't yet happened.