its all open and anyone can build that

If you're looking for a turn key solution, a company like Wavlake that handles everything is exactly what you want. Does Wavlake support your values? Do you mind giving them a 10% cut in exchange for the service they provide? If Wavlake works for you, use Wavlake, they're a great solution. But if you want more ownership, there's tools to do it yourself. It's like changing your oil. If you know how to do it, you can choose to do it yourself or pay someone else because it's not worth the hassle. No shade with either decision.