These cyclical "Bitcoin will never reach X price again" are great, because it puts things into perspective. It's fantastic to revisit these classics when they become deprecated as we do in fact reach new time highs.
It's also an excellent way to tell when people are being overly pessimistic, and therefore a bottom may be looming. Every time we have people saying we are going lower after a big crash is a sign of how you need to start getting ready to buy.
Long term predictions like bitcoin will reach X value by theb and then or bitcoin will never reach Y again are stupid because they are based on short term prepositions.
OP thinks that it will not reach 20k because if you look at last one or two months it really looks like growth stops when price reaches certain number but if you look at last two years we can agree that general trend is good so we can expect new ATH sooner or later
Bitcoin is for long term investment, we just see how it pumps last year that people putting too much expectation in it, but I believe that it is still able to do so, holding while doing trading of some alts works for me.