People are not spending their bitcoins for several reasons, some of this reasons are personal reasons, while the others are obvious, I am going to mention one of those personal reasons and one of the obvious reasons -
1. Most people still see bitcoin and cryptocurrencies in general as an investment vehicle rather than as a currency to be spent on goods and services just the same way we spend our fiat currency - this is a personal reason.
2. Look around you, you will discover that actually, not too many businesses and services accept bitcoin and other cryptocurrency payments, some businesses still think cryptocurrencies are scam, others think it's illegal, some other businesses that have interest in it do not know how to go about implementing crypto into their business, and maybe they are too busy to do the research needed, or maybe they are afraid not to fall or follow a wrong information that will lead to them being scammed.
So when there is just a small number of business and services accepting cryptocurrency payments, you discover that crypto holders have a very limited access to spending their crypto, since a business accepting crypto payments might not be close to them or might not even be in their area - this is an obvious reason.
The two reasons you mentioned are indeed the problem why until now not many people use crypto as a payment method. I myself more
comfortable buying goods and paying for services with fiat, because I have done it in the long term, and it becomes a habit that is hard
to change. Then knowing that crypto holdings can generate huge profits, of course I think it's better to use crypto for investment.
After all, my country prohibits the use of crypto as a means of payment, making me even more uncomfortable using crypto for payments.
So in the end if I want to spend the crypto I have, I will first convert the crypto to fiat. Maybe if there are many countries that support crypto
and legalize crypto as a legal tender, there will be many businesses and services that accept crypto payments. For now, let's just be grateful
that crypto is a profitable for investment.