Think of Bitcoin kind of like digital gold. People buy gold to protect against inflation, right? It keeps its value when regular money might lose it. Some folks see Bitcoin the same way - a shield against inflation because there's only so much of it and no one controls it. But here's the catch - Bitcoin's price jumps around a lot more than gold. So while it could be good against inflation, its rollercoaster prices make it a bit of a wild card.
The problem with Bitcoin is really the extreme nature of price swings. If you invest 1 Million USD in Bitcoin now to buy a house in 5 years time, you have no idea what the price of Bitcoin will be in 5 Years in USD maybe double what you paid or maybe only half of it..... If you really need cash in USD at a specific point in time, Bitcoin can cause you some issues..