Usually trading with demo is actually good but for a quicker process or fast learning methods I wouldn't encourage someone to use their demo instead it's better to at least spare little money to trade in real account because Demo and Live accounts aren't operated the same way, there is much difference when you trade on both realistic accounts and Non-realistic account, you gain more life experience compared to when you are trading on demo and of course you wouldn't be that focused on demo compared to how you be careful while trading with real money, I am talking out of experience.
I think using the demo for a new trader can be an alternative method. However, no one will be able to find any Exchanger Platform for Demo Trading. But do not encourage the Demo Trade as you say. But I think this is also very effective. Moreover, my friend uses various forex trading apps, there are only BTC and eth currency pair. And my friend made a lot of money through that app. Moreover, the big thing is that there is an option for demo trading. That app is (Expert Option, Exness). Yes, it is true that the amount of focus on a trader demo, and the real trade with much more attention. However, it is possible to achieve in all cases. Whether it is Demo Trade or Real Trade.