TLDR: having the right founder, the right timing, right product, right team, market are all complicated factors and even one of them could destroy the equity. It's worth asking why you need equity and also I recommend not thinking that everyone is a wizard in non-tech skills, people no matter how they might look from outside are still figuring things out from the inside. In that sense, instead of offloading it to someone else to be a founder of something and then trusting them. It's worth asking more questions. I wish you luck in the journey nonetheless whatever the road may be :-), Good luck!
I highly recommend the book "hard things about hard things" once for you to read about the non-technical aspects of the things.
I don't have answer to your exact scenario but my main point is that the book tries to show in my opinion, all the complexities involved in the project.
The book also mentions people who want equity but then suggests that unless every person on the team realizes that any percentage of zero is still zero and that the focus should be on making the company grow but at the same time I feel as if there are so many factors involved.
I feel as if you could ask for more equity than usual but having an Equity only job to me no matter how much FIRE still feels (personally) as a bit of an issue to me.
When you mention how you feel as if non-technical work is something that you aren't good at, how would you know the person you are working for could be genuinely good at it too (also this is a factor of sales not CEO functions, sales strategy between different stages of company is different, again I highly recommend reading the book)
But coming back to the point, its that there are so many factors and so much nuance within the success and as such working for co-founders creates an issue. Even if you have the best founder and everything is set, its still pretty unpredictable to be all in on equity and it could be a disaster for mild regret if suppose years are spent into building something and that equity turns to zero especially when it would be done with other person's direction given that you are suggesting to not be co-founder/founder.
I feel as if the evaluation of founder route is still something worth doing. We might be over-estimating how much other people know because they are figuring many things on the first time as well.
In short, I hope I am able to explain my point that it doesn't feel like a wise decision for me to go all in on equity even if you have money. It's worth asking if you already have the money, why bother with equity? is it to get even more rich or the chances of being insanely rich?, if so, why do you want to be such, for fame.
Or is the reason to actually create some genuine lasting impact (this seems likely to me), if this is the case then I could perhaps recommend non-profit work which could help you find that meaning and purpose.