Would you still recommend to friends to buy Bitcoin?

I used to recommend it because it is simply "the biggest crypto currency," so what can possibly go too wrong?

However, now with Microstrategy looking more and more like a ponzi I'm worried that once they blow up I might regret my endorsement

Microstrategy is merely one of millions of entities exchanging Bitcoin. The only way they or any single entity can permanently take down all of Bitcoin would be to take a majority of validators or miners.