What is the biggest bottleneck accounting firms face right now in scaling with AI, and what would 'leaning in' to AI actually require?

Multiple firm owners said their real bottleneck isn't software but people: there aren't enough good accountants, older practitioners are retiring without younger people entering the field, and one owner has more business than staff to handle despite never spending on marketing. The hope is that better software will scan source documents and automate the conversion from bookkeeping/cash data into tax-ready numbers, freeing staff to focus on tax planning and higher-value 'brain work' rather than manual bookkeeping and return prep. One participant estimated this kind of automation could mature within the next 18 months, but acknowledged 'we're not there yet.'