> You will have problems if you have the worst tech stack
Cool, so we've established that I'm saying the tech stack matters. All of the problems above have to do with the tech stack. Yes performance is part of your tech stack. Yes, how easily you can monitor it and is part of your tech stack.
> 99% of startups won't be able to afford the best developers anyway. 99% of startups don't need the best developers. Average developers can make great products.
Here again, the tech stack matters. If you have known mediocre developers, you should pick a language like Java or Go because otherwise it's going to be a mess. If you have good developers, you should trust them to pick the technologies.