Python is one of the most popular programming languages out there. It's no. 3 in the TIOBE index, and no. 4 in the 2020 Stack Overflow Developer survey ranking of the most popular technologies. Its popularity is consistently rising, too.
This isn't surprising, especially given the many areas in which Python works great.
You can use it for web development, and the many Python libraries available will make the experience easier. If you dive into machine learning, you'll learn that Python is the most popular language for that purpose.
Startups use it, because Python is scalable and reliable.
Fintechs use it, because it's high performing and has ready-made solutions they can use.
On top of all that, Python is a great programming language for beginners. It's quite easy to read, as it's not too far from actual English, and its syntax is clear.
Finally, there are the frameworks you can use when you go with Python, which can help you build your product faster. You get to choose from Django, a secure framework focused on delivering business value, Flask, a microframework you can customize freely, and many, many more.