They are only buying Bitcoin after they figured out that algorithmic design is flawed and attributing the downfall to Bitcoin is just so wrong.
This part is not correct, they bought all the Bitcoin before the collapse of the algorithmic stablecoin. It was not done because a design flaw was acknowledge, because if it was known at the time it would have collapsed right then. The Bitcoin buying has softened the complete collapse, it only had positive effects and not a single negative effect in this case. Users need to stop making up negative lies, buying Bitcoin is safe and a great strategy.
Wait... why should they even hold bitcoin?
Last I checked Tether aka USDT was a stablecoin that claims it has a swap rate of 1:1 with the US dollar (not with bitcoin). And it was supposed to be backed by US dollar. That means they should be bag-holding this shitfiat as the thing that backs their centralized stablecoin to be able to keep that ratio correct and be able to fulfill their obligation meaning if every single person who bagholds Tether wanted to get their fiat out, the company has to be able to pay them the fiat they are owed.
It does not make sense to ask this question at all, because what you are asking is essentially this. Why should someone super rich, in this case Tether, ever buy Bitcoin? Why should they buy gold? Why not just keep all in treasuries so USD? I mean I expect you to have some decent knowledge here, so the question that you are asking answers itself with many reasonable points. Or you also have something against this extremely successful company?

The discrepancy in the reserve report and the statement may not really contradict each other if the additional 50k is held as a corporate investment rather than as part of USDT’s reserves. What I do wonder now that they separated the holdings is how verifiable the additional bitcoin holdings are? The reserve attestation gives us info about the asset backing USDT at that time but we don’t really get a complete picture of Tethers wider financial position.
It does not matter how verifiable they are, because it is not relevant to you at all because it is not what is backing the stablecoin. Stop bothering private businesses that are rich. Nobody is snooping into your private affairs either. If it weren't for the benefits of marketing, it would be better for them to keep quiet like many companies that users on this forum have never ever heard of.
If you're new to this, just know that Tether has never had a proper audit of their reserves. Their version is called "attestation" and I think they did it every half year or so. And these are simply: "take our word for it, we have enough reserves, and they're good against out liabilities".
Not even done by a "Big Four" just some auditing firm. I read somewhere KPMG did do one for them last year or in 2024? People probably don't remember any longer how badly they measure up to proper reserve audits.
KPMG did it this year, for data completing the year 2025. It confirmed that they are as great as they say they are, and that critics are just envious of their success. So where is the problem? This is an attestation by one of the big 4 using the most recent complete financial data. A full audit is not necessary, it is usually required only if something wrong is detected or suspected.