Bitcoin is NOT a pyramid scheme. A pyramid scheme is FRAUD. Bitcoin is is a protocol and code that clearly states the limit of coins available. While any money system attracts bad players, Bitcoin (and most other top tier cryptos) and its honest participants are up front about the risks associated with crypto, and thus crypto (and bitcoin) is NOT a fraud.
Bitcoin is RISKY, and those who cannot stomach the high volatility should avoid it until such time as its value settles down.
The reason it is so risky and volatile is because the banking system has instituted harsh rules to its monopoly that extracts wealth from the world economies. Thus, bitcoin cannot be backed by one or more people without running afoul of these unfair rules. Thus, bitcoin and other crypto HAVE NO backing.
What's more, because the banking system has become the de facto monetary system, people have become lazy about protecting themselves against thieves and unscrupulous individuals. They've forgotten (or grown up) without the threat of theft and loss. They've grown gullible and soft.
My advice... avoid anything that deals with crypto unless you're savvy enough or can stomach a potential loss. You gamble when you touch crypto, so isolate it and be very warry of anything that may touch it, because it is UNREGULATED and lacks the typical protections that have made people gullible and soft.
In short, the mischaracterization of bitcoin as a pyramid scheme is unfounded and overblown. But the bad apples it has attracted warrants protecting yourself. What's more, because crypto is a threat to the banking system and governments, it is highly likely that these bad apples have been planted in the Bitcoin and crypto ecosystems to tarnish crypto. Those who want power will do all sorts of nafarious things to get more and keep it, so think for yourself and be discerning about what bitcoin is and is not.