Maybe they do.

I can't find a single reference on them that contains actual details on the computational model because the internet is full of vapid circular search bait, particularly about cryptocurrencies.

The last I checked, the BTC VM disabled most useful opcodes, which meant you couldn't actually make money automatically redeemable for a large number of constraints you would want to impose.

My quick search seems to support that the VM still disables many opcodes: https://en.bitcoin.it/wiki/Script