Why should i invest in bitcoin or other cryptos ?
It's maybe the same question like why you should drink more water, have enough sleep, eat vegetables etc. You will get the benefit for your health in the future if you did all of them.
Cryptocurrency is a future money/payment. Buy or hold them means you support the idea of cutting the third parties of payment transactions by joining the ecosystem. Now when more people joining and gain the marketcap, you get the benefit by increasing price.
1) The number reason everyone should buy or invest in Bitcoin or other cryptos is that the reign of fiat currency is coming to an end just like when the world change from gold to fiat, this is the reason why IMF advised the government to create CBDC.
2) Buy and holding crypto doesn't totally mean supporting the cutting of the third party's payment but it means been awakening for the future liberation.