The biggest issue limiting most government consider and majorly the reason why bitcoins adoption has been slow is in my opinion the anonymity involved and the inability for government to directly be a party to your transaction.
If there were no such issues, gaining widespread adoption will not even be a topic for discussion as it would have happened already or almost done being adopted I think.
Can the governments of the world let bitcoin become fully in use in their respective countries without pushing for lesser anonymity and a way for them to monitor the system?
It is claimed sometimes to be an obstacle, but it's not a very fair concern. For example, cash is not being tracked, people can largely use it with providing zero ID, and sometimes in significant amounts. Moreover, if the matter is IDs, one could try to legalize BTC but demand custodial wallets for it to be used as legal tender, of example. And yet it's not happening, not causing widespread adoption. I think there isn't enough interest in adopting Bitcoin, both in political circles and in populations, often. Also, volatility and scaling are sometimes major issues as well.