How can other players view my individual Kills & Deaths?

If you set tf_scoreboard_mouse_mode you can interact with it and click on another users name to view their stats.

tf_scoreboard_mouse_mode 1 tf_scoreboard_mouse_mode 2

https://wiki.teamfortress.com/wiki/Scoreboard#Enable_mouse_input_on_the_scoreboard

This was from ~3 years ago: https://www.reddit.com/r/tf2/comments/3ch15t/psa_the_scoreboard_has_a_new_mouse_mode/