Also, a lot of developers forget to it, but even if you start with a fast language down the line you will end up rewriting it. The problem is that requirements change a lot and because of that your application will often end up being a mess. For similar reason RDBMS is also better than NoSQL when starting a project.
When rewriting you already know how the project is now, so you can design your app around that, which makes things simpler and faster.
But solve the problem first, and solve it fast. It's why so many startups from the 2010's on used Ruby; they were productive in it, solving a real problem, rolling out features fast.
I've worked in a few projects where they dove onto the cargo cult, of wishing they had the kind of requests and load that e.g. a microservices architecture might help with. Massively overpriced projects too, because they hired lots of consultants and self-employed people.
The one time there was a guy who rocked up in a Maserati (used, lol); he took two weeks to build a page that was just a centered bit of text and a button, and it didn't even work.