It is a normal development that Bitcoin is getting stronger in a sustained bear market. Alts are getting destroyed and people flee them in masses. But most dont want to leave crypto, so bitcoin is a safe haven for the time being. Just dont be fooled and think this is going to stay like that.
Alts are getting destroyed for a good reason. Most of them are scams, and the others have no real leadership behind them. It's turning into a circus.
After either getting ripped off or hearing about friends being ripped off too many times, people have decided not to waste time on risky shit that is more likely to turn into a ponzi scheme than generate any return at all. Therefore we have bitcoin strength. It will last long because there is absolutely no trust in the altcoins. Bitcoin is much more reliable and everyone knows it.