When you think about and iterate judiciously in a problem domain over a decade instead of trying something different every day to see what sticks, you'll see you can get remarkably far.
Let me see, you've got Django, DRF, Flask, Flask-Restful, Flask-Restplus, Flask-API, sanic, pyramid, Cornice, hug, falcon, eve, bottle, tornado, aiohttp, vibora, weppy, starlette...
Those are just some that I've picked out of my head.
Routing requests and managing HTTP fundamentals is a solved problem. There is literally zero value in adding another framework when the real complexity is in business logic.
Django does routing, forms, ORM, templates, APIs, GIS, you name it. Flask is more minimialist and expects third-party package for this.
Django also has a very extensive ecosystem of libraries for managing the common web use cases.