We once have accostomed with some very convenient method around anything, we could never give it up, then eventually we anytime are as if slave are controled by convenience by itself.
E.g. password is typical it. However its use is very frequent then, necessarily we are obliged to keep very many passwords in mind, eventually, for pulling out each different password so immediately, another devise must be necessary, eventually, we could feel not so convenient reality again.

E.g. if we discover another better method to enter the sites, saliva authentication system would be easy and certain for transaction of incorrect tresspassing, but even it would be infringed by family members or so, presumably pioneering ones of authentication system might be thinking so.

Eventually, even if I think more convenient method must exist, if we try to set universally convenient way, only password would become the most generally convenient way, thereby, only password might never be switched to another entering authentication system.

Bio-metrix authentication system would cost so much for usage of very popular object for many people, then it could be used only for top secret professional object, possibly that standpoint could be present.

Anyway, for me, using very many different passwords is too troublesome to memorize all so exactly, another better and convenient, but very safe method would exist or not, everytime I use each subtly differentiated password, I think that thing repititiously.
(to be continued)
(Sep. 4th. 2020)