For business I don't think tech stack matters that much but for developers, it matters. Good and young developers avoid working on dull technologies as they don't see future in those.

Also, for hiring generally, more popular technology will get more quality candidates through the door.

If you outsource your initial product and become successful, you will inevitably bring development in house. I'm currently helping a company do a complete rewrite from PHP and docker shenanigans to languages that are easier to hire for and correct usage of a modern tool (containers).