Yes, but at the same time there are GAAP (generally accepted accounting principles), limiting how much you can change the methodologies, so you can rig only so much.
One of the new laws regarding accounting was daily mark-to-market accounting of assets and investments. $AMZN just took a $7.6B hit due to this ($RIVN write down). So it’s hit or miss. I remember Buffett complaining about this change a year back or so.
The accounting of "cryptocurrency" is still being developed, but, yes, Bitcoin holdings take an impairment when their value drops below a certain point. This doesn't typically affect cost basis. It may be deducted as losses on a tax return but that might impact cost basis. I've heard from other accountants (a year or so ago, so take this with a lump of salt) that some companies are trying to account for cryptocurrency as inventory, as a "hot asset," as cash equivalents, or as intangibles.