Flash was banned to protect the Google, Apple, Microsoft ap ecosystems. Todays mobile CPUs are an order of magnitude way more powerful than those of 10 years ago. The performance issue doesn't apply now.
As for bugs, they can be fixed and they could have been fixed with the passage of time.
The whole agenda of aiming to replace Flash with HTML5 and CSS was a dishonest fraud from the get go.
10 years on now and still nowhere near what was available 10 years ago.