If you think Bitcoin is going to go to zero, then yes, sell.  There are a lot of people out there who believe bitcoin's ultimate value is zero, so you wouldn't be alone with that opinion.

If you think bitcoin is here to stay and will never go away then hold.

What will most likely happen is the successor to bitcoin will rule the roost for some time to come once it is developed.  In fact, most coins won't be around in a few years, and in that time, coins/tokens with better technology will appear and cause other coins to go to zero or close to it.

Until the great bull market occurs in crypto, the debate on individual cryptos is pure speculation.  And until the bull market does occur, having debates on topics such as this are nearly useless as the market is so small now, the money men have no trouble manipulating the whole coin space at will.  We are in the abusive phase still.  Anyone holding long term understands this and ends up holding tighter.

To survive this phase, accumulate and hold for 3 to 5 years minimum.  Don't even contemplate the words buy, sell, profit, or loss.  Just hold.