Since Bitcoin is a decentralised currency, nobody can regulate it. However, it's access can be regulated to an extent by various governments to avoid frauds and its illegal use. For example, governments can introduce tough KYC approvals and bring strict policies related to cryptocurrencies, to regulate it indirectly.
every day we are moving towards centralization, to buy bitcoin using Fiat we use banks (banks are centralized) and then we use exchanges (exchanges are centralized) and then we trade in centralized exchanges or use in centralized casinos or buy something in store centralized online. it was inevitable that bitcoin in the end would be surrounded by centralization