I would assume that for most people, "spending time on your mental health" is not something you do in solitary as a 9-to-5 job. It is more likely to mean building friendships at work or elsewhere, working towards meaningful goals, and leaving time to rest your mind and body. If this precludes a 100% dedication to some startup idea, then that's just something to accept about onself. Everything else will just lead to nothing but burnout, which kills all capacity to contribute anyway. Stuff like having a positive influence on the people you meet can also be a contribution, and there can be personal value and gratification even outside of "contributions", such as simply learning something new (maybe even something without economic value). Personally, I feel like it's highly arguable whether yet another SV-style startup is likely to result in a net positive contribution to the world anyway. Often, the drive to optimize everything for productivity seems to stem more from a need to prove ones worth to oneself and a lottery player's fantasy of riches. I commend everyone that takes their inspiration from more than those things, in business or outside.