You could try something like a shop vacuum. Or I have seen a tool that one rolls across the lawn to pick up nuts, though I think it would work best on larger acorns rather than little ones.

https://www.amleo.com/pickup-wizard-for-small-fruits-and-nuts-34-inch-diameter-minimum/p/NW12/?kc=amlshop17n,&mkwid=sASi1PrTD%7Cdt&pcrid=177735599463&pkw=&pmt=&plc=&prd=NW12&gclid=EAIaIQobChMI9-a15a-H1wIV07XACh3SZw59EAQYBSABEgK-q_D_BwE

Or even a narrowly spaced rake might do the trick.

Rent trained squirrels.

Find yourself a toddler and a bucket.