2% is a lot! There's only fifty things you can invest 2% of GDP in before you occupy the entire economy. But the list of services people need, from food, water, shelter, heating, transportation, education, healthcare, communications, entertainment, mining, materials, construction, research, maintenance, legal services... there's a lot of things on that list. To allocate each one 1% or 2% of the economy may seem small, but pretty quickly you hit 100%.

Most of you have mentioned is not investment, but consumption. Investments means to use money to make more money in the future. Global investment rates are around 25 % of global GDP. Avarage return on investement ist about 10% per year. In other words: using 1% or 2% of GDP if its leads to an improvement in GDP of more than 0.1% or 0.2% next year would count as a success. I think to expect a productivity gain on this scale due to AI is not unrealistic for 2026.