In the past (~2016) I did the solutions architect associate and received many invites because of it...
After that, I founded a startup that didn't go well and I'm planning to return to the market in the next months (as swe or devops/sre) and in my preparation plan is, besides other things (practice algorithm, systems design...), take some certs:
All out of my pocket. I don't think this makes a huge technical difference, but it open doors, the process is great to learn and I also want to be prepared for future interviews, maybe a MANGA/FAANG? :)
I'm in a very similar situation. My partners have other business besides the startup and I believe this is one of the main problems that's blocking our growth.
I suggest you:
(1) to define tasks for your partners on a board (like trello), then just follow the tasks if they are being executed.
(2) to have a limit date for the startup to profit and grow, and if the date is not met think about leave the startup.