BTC and ETF's

So, with Saylor's purchase of another 5000 Bitcoin today for Microstrategy bringing their holding to somewhat North of 158000, who feels this has been done before institutional money sinks their teeth in?

The simple fact that roughly 19 out off the possible 21 million BTC have been mined already leaves me feeling that the few million left will rapidly get bought up by Blackrock and others in an almost retail-like fomo as soon as they become available, which will take some time due to the halvings. And I mean, over years and years.

Really, if as a lot of us believe, BTC is a safe (ish) store of wealth, shouldnt we be going all-in to stack whatever we can afford now, before the available supply dries up? The gold standard itself is less predictable than BTC surely, as for instance Russia may well have huge unmined reserves, which may explain the US embargo on Russian gold thats being hoarded and being used to back the Ruble, similar in use to how the Dollar used to be backed by bullion. Will ETF's in BTC work similarly? Because if so, and with its clearly defined supply, BTC's value could reach levels that are unimaginable.