After almost 3 years, BCH is still trading above its launch price and is the #4 coin by market cap. If anything it seems like it will just keep following BTC. If a coin is relevant enough to be alive and kicking during the next bubble, it will pump alongside it.
It's tempting to condemn and write off altcoins generally but history says those that do will miss out on massive gains. Who wants to do that?
BCH launch price was in range of $250-500, now it trades at $250, which I think is horrible for a cryptocurrency, since it's supposed to grow in the long run. If you switch to BTC price it's even worse, it's clear that BCH or almost any other altcoin performs worse than Bitcoin.
And last year BTC was trading in the low $3,000s right near its price when BCH was launched. So what? Doesn't say much about the long term.
I expect BCH/BTC to bubble alongside other altcoins in the next bullish cycle. I believe we're still in the very early stages of an ALT/BTC bull market. Let's see what happens over the next year or so.
The alt season is the only hope for altcoins to become relevant again, but there's no guarantee that it will come - we had two bullish periods for Bitcoin recently, and alts weren't following it as good as during the 2017 market.
That's how altcoin growth cycles work. The majority of the time, ALT/BTC pairs are ranging or downtrending. Their exponential growth happens over a very short period of time. This is similar to BTCUSD, which ranges/downtrends for years at a time and then enters short-lived parabolic bubbles.
In 2017 people seriously believed that an altcoin might overtake Bitcoin because it is "old technology", but today Bitcoin's dominance is undisputed. I really don't believe that there will be a repeat of an altcoin bubble, far too many people are growing disappointed with alts, both as investors and as users.
I see it more as a pendulum that swings back and forth. Everybody said altcoins were dead after the 2014-2015 bear too. Your sentiment (including your disbelief that altcoins can rise again) is indicative of the skepticism that occurs in early bull markets.