It is an issue simply because leetcode grinding makes me feel like all my 10+ years of commitment to my previous employer (often foolishly at the expense of my personal well-being) and all the things I have contributed and picked up on the way mean nothing / nada / zilch to my future prospective employers. The whole prep process makes me feel like I need to start from scratch and nothing that I did in the past matters at all. I find this extremely frustrating.