It would not end, but the price would not keep going upward for the lifetime, there are other coins in the industry and many more are launched on monthly basis.
This is a good time to invest in BTC, same can not be said after few years, because Bitcoin would reach it's Max limit and price would stay there.
Yes, I agree on your opinion. Bitcoin will never end, the value of it will change sometimes it's high and sometimes it is low. Not just Bitcoin but all tokens available in the market, the price or value of those are unpredictable. If you will read the story behind Bitcoin, you will know how they'd survive and still standing today.