No, logins should be harder in order to be secure. Hence the addition of 2FA (which is also incompatible with your proposal).
Now, of course, it depends on how sensible the data in that account is. I wouldn’t want this for my email account, for example, or online password manager, which are the entry gate to all my accounts. The Kagi search engine offers the possibility to login on another device via a session URL which you can copy-paste. And this is fine, if the site / app makes clear the dangers, implemented it securely, tracks and lists the sessions and allows you to invalidate a session for all devices, and you are fine with potentially disclosing the data for that account - which is not much, as they don’t log the searches, only the daily counts. And their use-case makes sense, people aren’t used to authenticating in order to search something on the internet.
No, logins should be harder in order to be secure. Hence the addition of 2FA (which is also incompatible with your proposal).
Now, of course, it depends on how sensible the data in that account is. I wouldn’t want this for my email account, for example, or online password manager, which are the entry gate to all my accounts. The Kagi search engine offers the possibility to login on another device via a session URL which you can copy-paste. And this is fine, if the site / app makes clear the dangers, implemented it securely, tracks and lists the sessions and allows you to invalidate a session for all devices, and you are fine with potentially disclosing the data for that account - which is not much, as they don’t log the searches, only the daily counts. And their use-case makes sense, people aren’t used to authenticating in order to search something on the internet.