Hi,
yes, ancient old and has been replaced with HTML5.
So far the theory. In reality, when it comes to servermanagement boards ( HP iLO, Dell iDRAC, Supermicro IPMI ) most of the HTML5 implementations are not working well. While simply KVM functionality will work, if you want a bit more ( ISO mount, media mount, … ) the feature is either not working at all or has major restrictions ( timeouts for example ) or very bad implemented, resulting in cruel performance.
So at least for this usecase, it would be nice if newer browsers could be used.
But of course i understand, that human resources are limited. And this is a use case of/for a very limited amount of people.
So we will just maintain the old environments and use them until the major vendor’s give their HTML5 implementations enough love.
Thank you for your reply, and sorry for the too long delay in mine!
Have a nice christmas days and turnover for 2024 ahead 
Greetings
Oliver