As block reward decreases, miners will be dependent on transaction fees to suffice for their electricity costs. By then, if the price of Bitcoin isn't high enough, it will lead to a further reduction as miners abandon their business because of the lack of profit. Thus it could be said that Bitcoin can either do very well or collapse completely in 2140.
Doesn't the Bitcoin system fail in this way or are there any other variables in play that stop such a breakdown?
Even though it appears you are a Waves spammer, I will just ask, for a coin that is 8 years old, is 2140 (123 years from now) really the near future?
For context, 123 years ago was 1894, how many currencies have survived in their original form from 1894 until now?
Anyway, if miners stop mining, we can keep the network going on a lot less mining power, it doesn't need to be anywhere near the level it is now.