There was a perception about the increase in the price of Bitcoin a few years ago. I think that the price has increased much faster than it has come to this day.
I think that those who invested some money in Bitcoin a few years ago have exceeded their investment expectations today.
Bitcoin investment does not guarantee any profit. Even if you hold it for a long time, there is no guarantee that you will make guaranteed profit, similarly there is no way to say that you will face a loss. However, if you can hold Bitcoin for a long time according to your ability, then you can definitely build a large Bitcoin portfolio that can help you become profitable in the long run. The price of Bitcoin has changed drastically in the past few years. This will continue in the future as well. But those who do not accumulate their Bitcoins after a long time may be the ones who may lose. If you have excess money after making necessary expenses, then investing in Bitcoin can be safer than any other platform.
Using the expression extra cash, left over cash, or discretionary income would have been more better than using excess money in your expression which sounds more ambiguous to me, it sounds more like one needs more than enough prior to starting bitcon investment since anyone can come in with as little as what can be called left over money when our basic needs has been taken care of.
Basically choice of words do matter in some areas including this thread as newbies might interpret things in a different sense so it's good to use a better choice of words yet as long as one is passing the right information it doesn't have to be all good English or perfect grammar in terms of expressions as this thread is open to everyone including non English native speakers hence we would not expect everyone to be on the same page with their choice of words.