Remembering death recalls that time is limited and actions have consequences. It encourages keeping promises, restoring rights, repenting promptly, and making better use of one's days.
For example, someone who has wronged another person should repair the harm rather than endlessly defer it. Learning, worshipping, serving people, and fulfilling lawful duties also prepare us for what lies ahead.
The expression تُحْفَةُ does not mean seeking death when life becomes difficult. The ethical point is preparation for the Hereafter through good conduct.