Then Browsers will have to Update so their Software is HTML5 Compliant. If you can watch Videos on YouTube then your Browser has HTML5.
Once Flash Player has exhausted Support which will be sometime in 2020 the next to become extinct is Java. Windows 12 will phase out Java and most low end versions of Windows 10 which were implemented when Windows 10 first came on to the Market. Windows 8.1 has already exhausted support. Exhausting Support means you can still use the Operating Systems but any Software made by Microsoft, Adobe and JRE in those eras will no longer provide updates for those Products.