I’m thinking that since Bitcoin price will be stable that time, Central bank will enter mining competition since Bitcoin transaction fee will be in demand and bank transfer will be useless since Bitcoin is possibly a legal tender already globally.
How do you know that BTC price will be stable then, or that bank transfers will be useless? Obviously you can't just guess with things like these, if BTC continues with this current growth it may be a legal tender in many countries by the time, but it is also possible that it won't. It is a very long time from now and many things could happen, some other decentralized currency created could even rival BTC by the time, we do not know, and the reason why op shouldn't have started another one of these threads.
I believe Bitcoin will be the most valuable asset on earth since it’s price will continue to increase everytime the inflation is increasing too. The price will be stable increasing gradually as inflation hits hard the fiat economy.
It may possibly happen the way you predict it, but it may not also. The world doesn't stop evolving, and even if BTC is indeed a special creation, who can say that by 2140 some asset or currency more special wouldn't have been created.