As with things like these, Ikigai is a tool. It may or may not be useful/relevant. Depends on the situation I suppose ¯\_(ツ)_/¯ YMMV
Frankl's thoughts are interesting but unfortunately he lost me at "Suffering is an ineradicable part of life". This seems true if and only if one identifies with one's body/mind. If one chooses to identify with say "life" and not a specific body/mind, suffering might be eradicable. Feel free to read up on the eastern wisdom traditions specifically Advaita Vedanta for a much better exposition than I can provide in this small text box :) Good luck!