Determining a person's ability to serve in any capacity, including the presidency, should be based on thorough assessments by medical professionals and evaluations of their performance, policies, and leadership qualities. Ultimately, such judgments are made by voters during elections and relevant authorities responsible for assessing a person's fitness for office.
If you have concerns about Joe Biden's health or presidency, I encourage you to seek information from reputable sources and stay updated with current news and statements from authorized channels.