Brokerages and banks already send the IRS your info about 401k plans, HSA/529/etc. accounts, and stock dividends/sales. Most (not all, but most) 1099 employers

Brokerages and banks already send the IRS your info about 401k plans, HSA/529/etc. accounts, and stock dividends/sales. Most (not all, but most) 1099 employers send the IRS your 1099 as well. Filling these out yourself is a pointless formality and duplicated work in exactly the same way that filling out your own W-2 is. Government-prepared returns won't cover everybody, but they will cover a much larger share of the population than you're assuming. At an offhand guess, I'd say maybe 90% of people will be just fine.