Supply of money will never be exhausted. After this bear market STRC will remain pegged for very long time, until next bear market and so on. When USD inevitably hyperinflates, the market cap of STRC will go to 0 compared to market cap of MSTR and USD dividends will loose meaning.
M2 does not take into the account whole eurodollar system and some other more creative ways how to create USD. FED tried to report M3, but after some time they gave up, because it was too difficult and also did not include all the USD (and defiantly not eurodollar).
M2 is mostly just USD in US real economy (commercial banks creating money for companies that actually build something)
(All the influencer who just discovered M2 and look at SP500/m2 and see top of the bubble may be proved wrong)