Widows Mite Report estimates that if the Church's reserve fund was used like the endowment policy at BYU, all Church expenditures would be covered forever without need for any more donations.
"Church Investments as a Financial Endowment (Fund)," Widows Mite Report, 2023, accessed September 28, 2023
. . .
By applying the same conservative endowment policy used at BYU:
All Church expenditures are covered - forever
with ~1B/yr left over to reinvest or give charitable aid
without asking members for "one dollar of donation" ever again
. . .