Cant i stay logged in to the launcher?

[Maniac]

Pretty annoying i always have to enter my password and login

[Komarimaru]

You can keep your Square Enix ID, but password is required each time, yes.

[BriTankie]

You can try custom launchers, they offer QoL improvements

[Replicant Six]

https://github.com/goatcorp/FFXIVQuickLauncher

It's a community made launcher which is used to manage and utilize some plugins. Also it logs you in automatically, no need to enter in your info every time.