Investing via mining bitcoin is not so profitable in first place. If you have prior experience then it is bit easier to get starting. Why people are not getting in crypto has multiple reasons. Reasons like many countries simply don't have the required infra to support for bitcoin purchase, selling and exchange. Like in Serb the laws are pretty strict against purchase/send currency from/to foreign country. Many people don't know about the bitcoin or crypto. false Knowledge about the crypto currencies has been propagated by some mainstream news(entertainment) media. Thus many people find it difficult to invest in bitcoin.
There are many economist who do not trust in the bitcoin, largely because of its unregulated nature. Many claims that price of bitcoin is unreasonably high.