I'm off the opinion AGI arrives late 2020s - 2030s

I don't think we will have to discover/invent something radically different to get to AGI. It's most likely going to come from things like;

• massive scaling (10s of trillions of parameters, 1000x more data than today's top model )
• making them more multimodal (can work with and understand audio, video, images, text, interact with software, control hardware parts etc.)
• improving Neural Network technology (improving AI's step by step reasoning, faster learning and shorter training times, improving memory etc.)
• optimising hardware (ASICCs for AI, neuromorphic computing etc)

Basically, exponentially scaling AI will lead to AGI within a decade. Scaling is the "missing piece".