As it's said, "Patience is a virtue". We as "hodlers" of Bitcoin should be patient in order to see better results in the future. But, what if Bitcoin never reaches a new ATH? Then, I'm afraid that most people "hodling" Bitcoin will lose all of their investment in the long run.
What are your thoughts?

That's completely a not-so-good mindset. Intelligent hodlers aren't settling for one option. You have to deal with bitcoin's price volatility, Waiting for a new ATH was somehow a good option but it wasn't as good as selling coins accordingly to the price movements as it gives you more options to take rather than just waiting for a once-settlement. In addition to this, it takes too much time (of course) that in such time length you might have probably earned some good-to-go profits, lastly you didn't have any piece of idea when ATH will come, right? What's much worse with this is that
"what if Bitcoin never reaches a new ATH?" Then what would you do? as you don't have any sort of options or plan b.